lib/silccore/silcpacket.c

   1 /*
   2
   3   silcpacket.c
   4
   5   Author: Pekka Riikonen <priikone@silcnet.org>
   6
   7   Copyright (C) 1997 - 2008 Pekka Riikonen
   8
   9   This program is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published by
  11   the Free Software Foundation; version 2 of the License.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18 */
  19 /*
  20  * Created: Fri Jul 25 18:52:14 1997
  21  */
  22 /* $Id$ */
  23
  24 #include "silc.h"
  25
  26 /************************** Types and definitions ***************************/
  27
  28 /* Per scheduler (which usually means per thread) data.  We put per scheduler
  29    data here for accessing without locking.  SILC Schedule dictates that
  30    tasks are dispatched in one thread, hence the per scheduler context. */
  31 typedef struct {
  32   SilcSchedule schedule;                 /* The scheduler */
  33   SilcPacketEngine engine;               /* Packet engine */
  34   SilcDList inbufs;                      /* Data inbut buffer list */
  35   SilcUInt32 stream_count;               /* Number of streams using this */
  36 } *SilcPacketEngineContext;
  37
  38 /* Packet engine */
  39 struct SilcPacketEngineStruct {
  40   SilcMutex lock;                        /* Engine lock */
  41   SilcRng rng;                           /* RNG for engine */
  42   SilcHashTable contexts;                /* Per scheduler contexts */
  43   SilcPacketCallbacks *callbacks;        /* Packet callbacks */
  44   void *callback_context;                /* Context for callbacks */
  45   SilcList streams;                      /* All streams in engine */
  46   SilcList packet_pool;                  /* Free list for received packets */
  47   SilcHashTable udp_remote;              /* UDP remote streams, or NULL */
  48   unsigned int local_is_router    : 1;
  49 };
  50
  51 /* Packet processor context */
  52 typedef struct SilcPacketProcessStruct {
  53   SilcPacketType *types;                 /* Packets to process */
  54   SilcPacketCallbacks *callbacks;        /* Callbacks or NULL */
  55   void *callback_context;
  56   SilcInt32 priority;                    /* Priority */
  57 } *SilcPacketProcess;
  58
  59 /* UDP remote stream tuple */
  60 typedef struct {
  61   char *remote_ip;                       /* Remote IP address */
  62   SilcUInt16 remote_port;                /* Remote port */
  63 } *SilcPacketRemoteUDP;
  64
  65 /* Packet stream */
  66 struct SilcPacketStreamStruct {
  67   struct SilcPacketStreamStruct *next;
  68   SilcPacketEngineContext sc;            /* Per scheduler context */
  69   SilcStream stream;                     /* Underlaying stream */
  70   SilcMutex lock;                        /* Packet stream lock */
  71   SilcDList process;                     /* Packet processors, or NULL */
  72   SilcPacketRemoteUDP remote_udp;        /* UDP remote stream tuple, or NULL */
  73   void *stream_context;                  /* Stream context */
  74   SilcBufferStruct outbuf;               /* Out buffer */
  75   SilcBuffer inbuf;                      /* Inbuf from inbuf list or NULL */
  76   SilcCipher send_key[2];                /* Sending key */
  77   SilcHmac send_hmac[2];                 /* Sending HMAC */
  78   SilcCipher receive_key[2];             /* Receiving key */
  79   SilcHmac receive_hmac[2];              /* Receiving HMAC */
  80   unsigned char *src_id;                 /* Source ID */
  81   unsigned char *dst_id;                 /* Destination ID */
  82   SilcUInt32 send_psn;                   /* Sending sequence */
  83   SilcUInt32 receive_psn;                /* Receiving sequence */
  84   SilcAtomic32 refcnt;                   /* Reference counter */
  85   SilcUInt8 sid;                         /* Security ID, set if IV included */
  86   unsigned int src_id_len  : 6;
  87   unsigned int src_id_type : 2;
  88   unsigned int dst_id_len  : 6;
  89   unsigned int dst_id_type : 2;
  90   unsigned int is_router   : 1;          /* Set if router stream */
  91   unsigned int destroyed   : 1;          /* Set if destroyed */
  92   unsigned int iv_included : 1;          /* Set if IV included */
  93   unsigned int udp         : 1;          /* UDP remote stream */
  94 };
  95
  96 /* Initial size of stream buffers */
  97 #define SILC_PACKET_DEFAULT_SIZE  1024
  98
  99 /* Header length without source and destination ID's. */
 100 #define SILC_PACKET_HEADER_LEN 10
 101
 102 /* Minimum length of SILC Packet Header. */
 103 #define SILC_PACKET_MIN_HEADER_LEN 16
 104 #define SILC_PACKET_MIN_HEADER_LEN_IV 32 + 1
 105
 106 /* Maximum padding length */
 107 #define SILC_PACKET_MAX_PADLEN 128
 108
 109 /* Default padding length */
 110 #define SILC_PACKET_DEFAULT_PADLEN 16
 111
 112 /* Minimum packet length */
 113 #define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
 114
 115 /* Returns true length of the packet. */
 116 #define SILC_PACKET_LENGTH(__packetdata, __ret_truelen, __ret_paddedlen) \
 117 do {                                                                     \
 118   SILC_GET16_MSB((__ret_truelen), (__packetdata));                       \
 119   (__ret_paddedlen) = (__ret_truelen) + (SilcUInt8)(__packetdata)[4];    \
 120 } while(0)
 121
 122 /* Calculates the data length with given header length.  This macro
 123    can be used to check whether the data_len with header_len exceeds
 124    SILC_PACKET_MAX_LEN.  If it does, this returns the new data_len
 125    so that the SILC_PACKET_MAX_LEN is not exceeded.  If the data_len
 126    plus header_len fits SILC_PACKET_MAX_LEN the returned data length
 127    is the data_len given as argument. */
 128 #define SILC_PACKET_DATALEN(data_len, header_len)                         \
 129   ((data_len + header_len) > SILC_PACKET_MAX_LEN ?                        \
 130    data_len - ((data_len + header_len) - SILC_PACKET_MAX_LEN) : data_len)
 131
 132 /* Calculates the length of the padding in the packet. */
 133 #define SILC_PACKET_PADLEN(__packetlen, __blocklen, __padlen)               \
 134 do {                                                                        \
 135   __padlen = (SILC_PACKET_DEFAULT_PADLEN - (__packetlen) %                  \
 136               ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN));  \
 137   if (__padlen < 8)                                                         \
 138     __padlen += ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN); \
 139 } while(0)
 140
 141 /* Returns the length of the padding up to the maximum length, which
 142    is 128 bytes.*/
 143 #define SILC_PACKET_PADLEN_MAX(__packetlen, __blocklen, __padlen)          \
 144 do {                                                                       \
 145   __padlen = (SILC_PACKET_MAX_PADLEN - (__packetlen) %                     \
 146               ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
 147 } while(0)
 148
 149 /* EOS callback */
 150 #define SILC_PACKET_CALLBACK_EOS(s)                                     \
 151 do {                                                                    \
 152   (s)->sc->engine->callbacks->eos((s)->sc->engine, s,                   \
 153                                   (s)->sc->engine->callback_context,    \
 154                                   (s)->stream_context);                 \
 155 } while(0)
 156
 157 /* Error callback */
 158 #define SILC_PACKET_CALLBACK_ERROR(s, err)                              \
 159 do {                                                                    \
 160   (s)->sc->engine->callbacks->error((s)->sc->engine, s, err,            \
 161                                     (s)->sc->engine->callback_context,  \
 162                                     (s)->stream_context);               \
 163 } while(0)
 164
 165 static SilcBool silc_packet_dispatch(SilcPacket packet);
 166 static void silc_packet_read_process(SilcPacketStream stream);
 167 static inline SilcBool silc_packet_send_raw(SilcPacketStream stream,
 168                                             SilcPacketType type,
 169                                             SilcPacketFlags flags,
 170                                             SilcIdType src_id_type,
 171                                             unsigned char *src_id,
 172                                             SilcUInt32 src_id_len,
 173                                             SilcIdType dst_id_type,
 174                                             unsigned char *dst_id,
 175                                             SilcUInt32 dst_id_len,
 176                                             const unsigned char *data,
 177                                             SilcUInt32 data_len,
 178                                             SilcCipher cipher,
 179                                             SilcHmac hmac);
 180
 181 /************************ Static utility functions **************************/
 182
 183 /* Injects packet to new stream created with silc_packet_stream_add_remote. */
 184
 185 SILC_TASK_CALLBACK(silc_packet_stream_inject_packet)
 186 {
 187   SilcPacket packet = context;
 188   SilcPacketStream stream = packet->stream;
 189
 190   SILC_LOG_DEBUG(("Injecting packet %p to stream %p", packet, packet->stream));
 191
 192   silc_mutex_lock(stream->lock);
 193   if (!stream->destroyed)
 194     silc_packet_dispatch(packet);
 195   silc_mutex_unlock(stream->lock);
 196   silc_packet_stream_unref(stream);
 197 }
 198
 199 /* Write data to the stream.  Must be called with ps->lock locked.  Unlocks
 200    the lock inside this function, unless no_unlock is TRUE.  Unlocks always
 201    in case it returns FALSE. */
 202
 203 static inline SilcBool silc_packet_stream_write(SilcPacketStream ps,
 204                                                 SilcBool no_unlock)
 205 {
 206   SilcStream stream;
 207   SilcBool connected;
 208   int i;
 209
 210   if (ps->udp)
 211     stream = ((SilcPacketStream)ps->stream)->stream;
 212   else
 213     stream = ps->stream;
 214
 215   if (ps->udp && silc_socket_stream_is_udp(stream, &connected)) {
 216     if (!connected) {
 217       /* Connectionless UDP stream */
 218       while (silc_buffer_len(&ps->outbuf) > 0) {
 219         i = silc_net_udp_send(stream, ps->remote_udp->remote_ip,
 220                               ps->remote_udp->remote_port,
 221                               ps->outbuf.data, silc_buffer_len(&ps->outbuf));
 222         if (silc_unlikely(i == -2)) {
 223           /* Error */
 224           silc_buffer_reset(&ps->outbuf);
 225           SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_WRITE);
 226           return FALSE;
 227         }
 228
 229         if (silc_unlikely(i == -1)) {
 230           /* Cannot write now, write later. */
 231           if (!no_unlock)
 232             silc_mutex_unlock(ps->lock);
 233           return TRUE;
 234         }
 235
 236         /* Wrote data */
 237         silc_buffer_pull(&ps->outbuf, i);
 238       }
 239
 240       silc_buffer_reset(&ps->outbuf);
 241       if (!no_unlock)
 242         silc_mutex_unlock(ps->lock);
 243
 244       return TRUE;
 245     }
 246   }
 247
 248   /* Write the data to the stream */
 249   while (silc_buffer_len(&ps->outbuf) > 0) {
 250     i = silc_stream_write(stream, ps->outbuf.data,
 251                           silc_buffer_len(&ps->outbuf));
 252     if (silc_unlikely(i == 0)) {
 253       /* EOS */
 254       silc_buffer_reset(&ps->outbuf);
 255       silc_mutex_unlock(ps->lock);
 256       SILC_PACKET_CALLBACK_EOS(ps);
 257       return FALSE;
 258     }
 259
 260     if (silc_unlikely(i == -2)) {
 261       /* Error */
 262       silc_buffer_reset(&ps->outbuf);
 263       silc_mutex_unlock(ps->lock);
 264       SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_WRITE);
 265       return FALSE;
 266     }
 267
 268     if (silc_unlikely(i == -1)) {
 269       /* Cannot write now, write later. */
 270       if (!no_unlock)
 271         silc_mutex_unlock(ps->lock);
 272       return TRUE;
 273     }
 274
 275     /* Wrote data */
 276     silc_buffer_pull(&ps->outbuf, i);
 277   }
 278
 279   silc_buffer_reset(&ps->outbuf);
 280   if (!no_unlock)
 281     silc_mutex_unlock(ps->lock);
 282
 283   return TRUE;
 284 }
 285
 286 /* Reads data from stream.  Must be called with ps->lock locked.  If this
 287    returns FALSE the lock has been unlocked.  If this returns packet stream
 288    to `ret_ps' its lock has been acquired and `ps' lock has been unlocked.
 289    It is returned if the stream is UDP and remote UDP stream exists for
 290    the sender of the packet. */
 291
 292 static inline SilcBool silc_packet_stream_read(SilcPacketStream ps,
 293                                                SilcPacketStream *ret_ps)
 294 {
 295   SilcStream stream = ps->stream;
 296   SilcBuffer inbuf;
 297   SilcBool connected;
 298   int ret;
 299
 300   /* Get inbuf.  If there is already some data for this stream in the buffer
 301      we already have it.  Otherwise get the current one from list, it will
 302      include the data. */
 303   inbuf = ps->inbuf;
 304   if (!inbuf) {
 305     silc_dlist_start(ps->sc->inbufs);
 306     inbuf = silc_dlist_get(ps->sc->inbufs);
 307     if (!inbuf) {
 308       /* Allocate new data input buffer */
 309       inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE * 65);
 310       if (!inbuf) {
 311         silc_mutex_unlock(ps->lock);
 312         return FALSE;
 313       }
 314       silc_buffer_reset(inbuf);
 315       silc_dlist_add(ps->sc->inbufs, inbuf);
 316     }
 317   }
 318
 319   /* Make sure there is enough room to read */
 320   if (SILC_PACKET_DEFAULT_SIZE * 2 > silc_buffer_taillen(inbuf))
 321     silc_buffer_realloc(inbuf, silc_buffer_truelen(inbuf) +
 322                         (SILC_PACKET_DEFAULT_SIZE * 2));
 323
 324   if (silc_socket_stream_is_udp(stream, &connected)) {
 325     if (!connected) {
 326       /* Connectionless UDP stream, read one UDP packet */
 327       char remote_ip[64], tuple[64];
 328       int remote_port;
 329       SilcPacketStream remote;
 330
 331       ret = silc_net_udp_receive(stream, remote_ip, sizeof(remote_ip),
 332                                  &remote_port, inbuf->tail,
 333                                  silc_buffer_taillen(inbuf));
 334
 335       if (silc_unlikely(ret < 0)) {
 336         silc_mutex_unlock(ps->lock);
 337         if (ret == -1) {
 338           /* Cannot read now, do it later. */
 339           return FALSE;
 340         }
 341
 342         /* Error */
 343         silc_buffer_reset(inbuf);
 344         SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_READ);
 345         return FALSE;
 346       }
 347
 348       /* See if remote packet stream exist for this sender */
 349       silc_snprintf(tuple, sizeof(tuple), "%d%s", remote_port, remote_ip);
 350       silc_mutex_lock(ps->sc->engine->lock);
 351       if (silc_hash_table_find(ps->sc->engine->udp_remote, tuple, NULL,
 352                                (void *)&remote)) {
 353         silc_mutex_unlock(ps->sc->engine->lock);
 354         SILC_LOG_DEBUG(("UDP packet from %s:%d for stream %p", remote_ip,
 355                         remote_port, remote));
 356         silc_mutex_unlock(ps->lock);
 357         silc_mutex_lock(remote->lock);
 358         *ret_ps = remote;
 359         return TRUE;
 360       }
 361       silc_mutex_unlock(ps->sc->engine->lock);
 362
 363       /* Unknown sender */
 364       if (!ps->remote_udp) {
 365         ps->remote_udp = silc_calloc(1, sizeof(*ps->remote_udp));
 366         if (silc_unlikely(!ps->remote_udp)) {
 367           silc_mutex_unlock(ps->lock);
 368           SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_NO_MEMORY);
 369           return FALSE;
 370         }
 371       }
 372
 373       /* Save sender IP and port */
 374       silc_free(ps->remote_udp->remote_ip);
 375       ps->remote_udp->remote_ip = strdup(remote_ip);
 376       ps->remote_udp->remote_port = remote_port;
 377
 378       silc_buffer_pull_tail(inbuf, ret);
 379       return TRUE;
 380     }
 381   }
 382
 383   /* Read data from the stream */
 384   ret = silc_stream_read(stream, inbuf->tail, silc_buffer_taillen(inbuf));
 385   if (silc_unlikely(ret <= 0)) {
 386     silc_mutex_unlock(ps->lock);
 387     if (ret == 0) {
 388       /* EOS */
 389       silc_buffer_reset(inbuf);
 390       SILC_PACKET_CALLBACK_EOS(ps);
 391       return FALSE;
 392     }
 393
 394     if (ret == -1) {
 395       /* Cannot read now, do it later. */
 396       return FALSE;
 397     }
 398
 399     /* Error */
 400     silc_buffer_reset(inbuf);
 401     SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_READ);
 402     return FALSE;
 403   }
 404
 405   silc_buffer_pull_tail(inbuf, ret);
 406   return TRUE;
 407 }
 408
 409 /* Our stream IO notifier callback. */
 410
 411 static void silc_packet_stream_io(SilcStream stream, SilcStreamStatus status,
 412                                   void *context)
 413 {
 414   SilcPacketStream remote = NULL, ps = context;
 415
 416   silc_mutex_lock(ps->lock);
 417
 418   if (silc_unlikely(ps->destroyed)) {
 419     silc_mutex_unlock(ps->lock);
 420     return;
 421   }
 422
 423   switch (status) {
 424   case SILC_STREAM_CAN_READ:
 425     /* Reading is locked also with stream->lock because we may be reading
 426        at the same time other thread is writing to same underlaying stream. */
 427     SILC_LOG_DEBUG(("Reading data from stream %p, ps %p", ps->stream, ps));
 428
 429     /* Read data from stream */
 430     if (!silc_packet_stream_read(ps, &remote))
 431       return;
 432
 433     /* Now process the data */
 434     silc_packet_stream_ref(ps);
 435     if (!remote) {
 436       silc_packet_read_process(ps);
 437       silc_mutex_unlock(ps->lock);
 438     } else {
 439       silc_packet_read_process(remote);
 440       silc_mutex_unlock(remote->lock);
 441     }
 442     silc_packet_stream_unref(ps);
 443     break;
 444
 445   case SILC_STREAM_CAN_WRITE:
 446     SILC_LOG_DEBUG(("Writing pending data to stream %p, ps %p",
 447                     ps->stream, ps));
 448
 449     if (silc_unlikely(!silc_buffer_headlen(&ps->outbuf))) {
 450       silc_mutex_unlock(ps->lock);
 451       return;
 452     }
 453
 454     /* Write pending data to stream */
 455     silc_packet_stream_write(ps, FALSE);
 456     break;
 457
 458   default:
 459     silc_mutex_unlock(ps->lock);
 460     break;
 461   }
 462 }
 463
 464 /* Allocate packet */
 465
 466 static SilcPacket silc_packet_alloc(SilcPacketEngine engine)
 467 {
 468   SilcPacket packet;
 469
 470   SILC_LOG_DEBUG(("Packet pool count %d",
 471                   silc_list_count(engine->packet_pool)));
 472
 473   silc_mutex_lock(engine->lock);
 474
 475   /* Get packet from freelist or allocate new one. */
 476   packet = silc_list_get(engine->packet_pool);
 477   if (!packet) {
 478     void *tmp;
 479
 480     silc_mutex_unlock(engine->lock);
 481
 482     packet = silc_calloc(1, sizeof(*packet));
 483     if (silc_unlikely(!packet))
 484       return NULL;
 485
 486     SILC_LOG_DEBUG(("Allocating new packet %p", packet));
 487
 488     tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 489     if (silc_unlikely(!tmp)) {
 490       silc_free(packet);
 491       return NULL;
 492     }
 493     silc_buffer_set(&packet->buffer, tmp, SILC_PACKET_DEFAULT_SIZE);
 494     silc_buffer_reset(&packet->buffer);
 495
 496     return packet;
 497   }
 498
 499   SILC_LOG_DEBUG(("Get packet %p", packet));
 500
 501   /* Delete from freelist */
 502   silc_list_del(engine->packet_pool, packet);
 503
 504   silc_mutex_unlock(engine->lock);
 505
 506   return packet;
 507 }
 508
 509 /* UDP remote stream hash table destructor */
 510
 511 static void silc_packet_engine_hash_destr(void *key, void *context,
 512                                           void *user_context)
 513 {
 514   silc_free(key);
 515 }
 516
 517 /* Per scheduler context hash table destructor */
 518
 519 static void silc_packet_engine_context_destr(void *key, void *context,
 520                                              void *user_context)
 521 {
 522   SilcPacketEngineContext sc = context;
 523   SilcBuffer buffer;
 524
 525   silc_dlist_start(sc->inbufs);
 526   while ((buffer = silc_dlist_get(sc->inbufs))) {
 527     silc_buffer_clear(buffer);
 528     silc_buffer_free(buffer);
 529     silc_dlist_del(sc->inbufs, buffer);
 530   }
 531
 532   silc_dlist_uninit(sc->inbufs);
 533   silc_free(sc);
 534 }
 535
 536
 537 /******************************** Packet API ********************************/
 538
 539 /* Allocate new packet engine */
 540
 541 SilcPacketEngine
 542 silc_packet_engine_start(SilcRng rng, SilcBool router,
 543                          SilcPacketCallbacks *callbacks,
 544                          void *callback_context)
 545 {
 546   SilcPacketEngine engine;
 547   SilcPacket packet;
 548   int i;
 549   void *tmp;
 550
 551   SILC_LOG_DEBUG(("Starting new packet engine"));
 552
 553   if (!callbacks)
 554     return NULL;
 555   if (!callbacks->packet_receive || !callbacks->eos || !callbacks->error)
 556     return NULL;
 557
 558   engine = silc_calloc(1, sizeof(*engine));
 559   if (!engine)
 560     return NULL;
 561
 562   engine->contexts = silc_hash_table_alloc(0, silc_hash_ptr, NULL, NULL, NULL,
 563                                            silc_packet_engine_context_destr,
 564                                            engine, TRUE);
 565   if (!engine->contexts) {
 566     silc_free(engine);
 567     return NULL;
 568   }
 569
 570   engine->rng = rng;
 571   engine->local_is_router = router;
 572   engine->callbacks = callbacks;
 573   engine->callback_context = callback_context;
 574   silc_list_init(engine->streams, struct SilcPacketStreamStruct, next);
 575   silc_mutex_alloc(&engine->lock);
 576
 577   /* Allocate packet free list */
 578   silc_list_init(engine->packet_pool, struct SilcPacketStruct, next);
 579   for (i = 0; i < 5; i++) {
 580     packet = silc_calloc(1, sizeof(*packet));
 581     if (!packet) {
 582       silc_packet_engine_stop(engine);
 583       return NULL;
 584     }
 585
 586     tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 587     if (!tmp) {
 588       silc_packet_engine_stop(engine);
 589       return NULL;
 590     }
 591     silc_buffer_set(&packet->buffer, tmp, SILC_PACKET_DEFAULT_SIZE);
 592     silc_buffer_reset(&packet->buffer);
 593
 594     silc_list_add(engine->packet_pool, packet);
 595   }
 596   silc_list_start(engine->packet_pool);
 597
 598   return engine;
 599 }
 600
 601 /* Stop packet engine */
 602
 603 void silc_packet_engine_stop(SilcPacketEngine engine)
 604 {
 605   SilcPacket packet;
 606
 607   SILC_LOG_DEBUG(("Stopping packet engine"));
 608
 609   if (!engine)
 610     return;
 611
 612   /* Free packet free list */
 613   silc_list_start(engine->packet_pool);
 614   while ((packet = silc_list_get(engine->packet_pool))) {
 615     silc_buffer_purge(&packet->buffer);
 616     silc_free(packet);
 617   }
 618
 619   silc_hash_table_free(engine->contexts);
 620   silc_mutex_free(engine->lock);
 621   silc_free(engine);
 622 }
 623
 624 static const char * const packet_error[] = {
 625   "Cannot read from stream",
 626   "Cannot write to stream",
 627   "Packet MAC failed",
 628   "Packet decryption failed",
 629   "Unknown SID",
 630   "Packet is malformed",
 631   "System out of memory",
 632 };
 633
 634 /* Return packet error string */
 635
 636 const char *silc_packet_error_string(SilcPacketError error)
 637 {
 638   if (error < SILC_PACKET_ERR_READ || error > SILC_PACKET_ERR_NO_MEMORY)
 639     return "<invalid error code>";
 640   return packet_error[error];
 641 }
 642
 643 /* Return list of packet streams in the engine */
 644
 645 SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine)
 646 {
 647   SilcDList list;
 648   SilcPacketStream ps;
 649
 650   list = silc_dlist_init();
 651   if (!list)
 652     return NULL;
 653
 654   silc_mutex_lock(engine->lock);
 655   silc_list_start(engine->streams);
 656   while ((ps = silc_list_get(engine->streams))) {
 657     silc_packet_stream_ref(ps);
 658     silc_dlist_add(list, ps);
 659   }
 660   silc_mutex_unlock(engine->lock);
 661
 662   return list;
 663 }
 664
 665 /* Free list returned by silc_packet_engine_get_streams */
 666
 667 void silc_packet_engine_free_streams_list(SilcDList streams)
 668 {
 669   SilcPacketStream ps;
 670
 671   silc_dlist_start(streams);
 672   while ((ps = silc_dlist_get(streams)))
 673     silc_packet_stream_unref(ps);
 674
 675   silc_dlist_uninit(streams);
 676 }
 677
 678 /* Create new packet stream */
 679
 680 SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
 681                                            SilcSchedule schedule,
 682                                            SilcStream stream)
 683 {
 684   SilcPacketStream ps;
 685   SilcBuffer inbuf;
 686   void *tmp;
 687
 688   SILC_LOG_DEBUG(("Creating new packet stream"));
 689
 690   if (!engine || !stream)
 691     return NULL;
 692
 693   ps = silc_calloc(1, sizeof(*ps));
 694   if (!ps)
 695     return NULL;
 696
 697   ps->stream = stream;
 698   silc_atomic_init32(&ps->refcnt, 1);
 699   silc_mutex_alloc(&ps->lock);
 700
 701   /* Allocate out buffer */
 702   tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 703   if (!tmp) {
 704     silc_packet_stream_destroy(ps);
 705     return NULL;
 706   }
 707   silc_buffer_set(&ps->outbuf, tmp, SILC_PACKET_DEFAULT_SIZE);
 708   silc_buffer_reset(&ps->outbuf);
 709
 710   /* Initialize packet procesors list */
 711   ps->process = silc_dlist_init();
 712   if (!ps->process) {
 713     silc_packet_stream_destroy(ps);
 714     return NULL;
 715   }
 716
 717   silc_mutex_lock(engine->lock);
 718
 719   /* Add per scheduler context */
 720   if (!silc_hash_table_find(engine->contexts, schedule, NULL,
 721                             (void *)&ps->sc)) {
 722     ps->sc = silc_calloc(1, sizeof(*ps->sc));
 723     if (!ps->sc) {
 724       silc_mutex_unlock(engine->lock);
 725       silc_packet_stream_destroy(ps);
 726       return NULL;
 727     }
 728     ps->sc->engine = engine;
 729     ps->sc->schedule = schedule;
 730
 731     /* Allocate data input buffer */
 732     inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE * 65);
 733     if (!inbuf) {
 734       silc_free(ps->sc);
 735       ps->sc = NULL;
 736       silc_mutex_unlock(engine->lock);
 737       silc_packet_stream_destroy(ps);
 738       return NULL;
 739     }
 740     silc_buffer_reset(inbuf);
 741
 742     ps->sc->inbufs = silc_dlist_init();
 743     if (!ps->sc->inbufs) {
 744       silc_buffer_free(inbuf);
 745       silc_free(ps->sc);
 746       ps->sc = NULL;
 747       silc_mutex_unlock(engine->lock);
 748       silc_packet_stream_destroy(ps);
 749       return NULL;
 750     }
 751     silc_dlist_add(ps->sc->inbufs, inbuf);
 752
 753     /* Add to per scheduler context hash table */
 754     if (!silc_hash_table_add(engine->contexts, schedule, ps->sc)) {
 755       silc_buffer_free(inbuf);
 756       silc_dlist_del(ps->sc->inbufs, inbuf);
 757       silc_free(ps->sc);
 758       ps->sc = NULL;
 759       silc_mutex_unlock(engine->lock);
 760       silc_packet_stream_destroy(ps);
 761       return NULL;
 762     }
 763   }
 764   ps->sc->stream_count++;
 765
 766   /* Add the packet stream to engine */
 767   silc_list_add(engine->streams, ps);
 768
 769   /* If this is UDP stream, allocate UDP remote stream hash table */
 770   if (!engine->udp_remote && silc_socket_stream_is_udp(stream, NULL))
 771     engine->udp_remote = silc_hash_table_alloc(0, silc_hash_string, NULL,
 772                                                silc_hash_string_compare, NULL,
 773                                                silc_packet_engine_hash_destr,
 774                                                NULL, TRUE);
 775
 776   silc_mutex_unlock(engine->lock);
 777
 778   /* Set IO notifier callback.  This schedules this stream for I/O. */
 779   if (!silc_stream_set_notifier(ps->stream, schedule,
 780                                 silc_packet_stream_io, ps)) {
 781     SILC_LOG_DEBUG(("Cannot set stream notifier for packet stream"));
 782     silc_packet_stream_destroy(ps);
 783     return NULL;
 784   }
 785
 786   SILC_LOG_DEBUG(("Created packet stream %p", ps));
 787
 788   return ps;
 789 }
 790
 791 /* Add new remote packet stream for UDP packet streams */
 792
 793 SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
 794                                                const char *remote_ip,
 795                                                SilcUInt16 remote_port,
 796                                                SilcPacket packet)
 797 {
 798   SilcPacketEngine engine = stream->sc->engine;
 799   SilcPacketStream ps;
 800   char *tuple;
 801   void *tmp;
 802
 803   SILC_LOG_DEBUG(("Adding UDP remote %s:%d to packet stream %p",
 804                   remote_ip, remote_port, stream));
 805
 806   if (!stream || !remote_ip || !remote_port)
 807     return NULL;
 808
 809   if (!silc_socket_stream_is_udp(stream->stream, NULL)) {
 810     SILC_LOG_ERROR(("Stream is not UDP stream, cannot add remote IP"));
 811     return NULL;
 812   }
 813
 814   ps = silc_calloc(1, sizeof(*ps));
 815   if (!ps)
 816     return NULL;
 817   ps->sc = stream->sc;
 818
 819   silc_atomic_init32(&ps->refcnt, 1);
 820   silc_mutex_alloc(&ps->lock);
 821
 822   /* Set the UDP packet stream as underlaying stream */
 823   silc_packet_stream_ref(stream);
 824   ps->stream = (SilcStream)stream;
 825   ps->udp = TRUE;
 826
 827   /* Allocate out buffer */
 828   tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 829   if (!tmp) {
 830     silc_packet_stream_destroy(ps);
 831     return NULL;
 832   }
 833   silc_buffer_set(&ps->outbuf, tmp, SILC_PACKET_DEFAULT_SIZE);
 834   silc_buffer_reset(&ps->outbuf);
 835
 836   /* Initialize packet procesors list */
 837   ps->process = silc_dlist_init();
 838   if (!ps->process) {
 839     silc_packet_stream_destroy(ps);
 840     return NULL;
 841   }
 842
 843   /* Add to engine with this IP and port pair */
 844   tuple = silc_format("%d%s", remote_port, remote_ip);
 845   silc_mutex_lock(engine->lock);
 846   if (!tuple || !silc_hash_table_add(engine->udp_remote, tuple, ps)) {
 847     silc_mutex_unlock(engine->lock);
 848     silc_packet_stream_destroy(ps);
 849     return NULL;
 850   }
 851   silc_mutex_unlock(engine->lock);
 852
 853   /* Save remote IP and port pair */
 854   ps->remote_udp = silc_calloc(1, sizeof(*ps->remote_udp));
 855   if (!ps->remote_udp) {
 856     silc_packet_stream_destroy(ps);
 857     return NULL;
 858   }
 859   ps->remote_udp->remote_port = remote_port;
 860   ps->remote_udp->remote_ip = strdup(remote_ip);
 861   if (!ps->remote_udp->remote_ip) {
 862     silc_packet_stream_destroy(ps);
 863     return NULL;
 864   }
 865
 866   if (packet) {
 867     /* Inject packet to the new stream */
 868     packet->stream = ps;
 869     silc_packet_stream_ref(ps);
 870     silc_schedule_task_add_timeout(silc_stream_get_schedule(stream->stream),
 871                                    silc_packet_stream_inject_packet, packet,
 872                                    0, 0);
 873   }
 874
 875   return ps;
 876 }
 877
 878 /* Destroy packet stream */
 879
 880 void silc_packet_stream_destroy(SilcPacketStream stream)
 881 {
 882   SilcPacketEngine engine;
 883
 884   if (!stream)
 885     return;
 886
 887   if (silc_atomic_sub_int32(&stream->refcnt, 1) > 0) {
 888     if (stream->destroyed)
 889       return;
 890     stream->destroyed = TRUE;
 891
 892     SILC_LOG_DEBUG(("Marking packet stream %p destroyed", stream));
 893
 894     /* Close the underlaying stream */
 895     if (!stream->udp && stream->stream)
 896       silc_stream_close(stream->stream);
 897     return;
 898   }
 899
 900   SILC_LOG_DEBUG(("Destroying packet stream %p", stream));
 901
 902   if (!stream->udp) {
 903     /* Delete from engine */
 904     if (stream->sc) {
 905       engine = stream->sc->engine;
 906       silc_mutex_lock(engine->lock);
 907       silc_list_del(engine->streams, stream);
 908
 909       /* Remove per scheduler context, if it is not used anymore */
 910       stream->sc->stream_count--;
 911       if (!stream->sc->stream_count)
 912         silc_hash_table_del(engine->contexts, stream->sc->schedule);
 913
 914       silc_mutex_unlock(engine->lock);
 915     }
 916
 917     /* Destroy the underlaying stream */
 918     if (stream->stream)
 919       silc_stream_destroy(stream->stream);
 920   } else {
 921     /* Delete from UDP remote hash table */
 922     char tuple[64];
 923     engine = stream->sc->engine;
 924     silc_snprintf(tuple, sizeof(tuple), "%d%s",
 925                   stream->remote_udp->remote_port,
 926                   stream->remote_udp->remote_ip);
 927     silc_mutex_lock(engine->lock);
 928     silc_hash_table_del(engine->udp_remote, tuple);
 929     silc_mutex_unlock(engine->lock);
 930
 931     silc_free(stream->remote_udp->remote_ip);
 932     silc_free(stream->remote_udp);
 933
 934     /* Unreference the underlaying packet stream */
 935     silc_packet_stream_unref((SilcPacketStream)stream->stream);
 936   }
 937
 938   /* Clear and free buffers */
 939   silc_buffer_clear(&stream->outbuf);
 940   silc_buffer_purge(&stream->outbuf);
 941
 942   if (stream->process) {
 943     SilcPacketProcess p;
 944     silc_dlist_start(stream->process);
 945     while ((p = silc_dlist_get(stream->process))) {
 946       silc_free(p->types);
 947       silc_free(p);
 948       silc_dlist_del(stream->process, p);
 949     }
 950     silc_dlist_uninit(stream->process);
 951   }
 952
 953   /* Destroy ciphers and HMACs */
 954   if (stream->send_key[0])
 955     silc_cipher_free(stream->send_key[0]);
 956   if (stream->receive_key[0])
 957     silc_cipher_free(stream->receive_key[0]);
 958   if (stream->send_hmac[0])
 959     silc_hmac_free(stream->send_hmac[0]);
 960   if (stream->receive_hmac[0])
 961     silc_hmac_free(stream->receive_hmac[0]);
 962   if (stream->send_key[1])
 963     silc_cipher_free(stream->send_key[1]);
 964   if (stream->receive_key[1])
 965     silc_cipher_free(stream->receive_key[1]);
 966   if (stream->send_hmac[1])
 967     silc_hmac_free(stream->send_hmac[1]);
 968   if (stream->receive_hmac[1])
 969     silc_hmac_free(stream->receive_hmac[1]);
 970
 971   /* Free IDs */
 972   silc_free(stream->src_id);
 973   silc_free(stream->dst_id);
 974
 975   silc_atomic_uninit32(&stream->refcnt);
 976   silc_mutex_free(stream->lock);
 977   silc_free(stream);
 978 }
 979
 980 /* Return TRUE if the stream is valid */
 981
 982 SilcBool silc_packet_stream_is_valid(SilcPacketStream stream)
 983 {
 984   return stream->destroyed == FALSE;
 985 }
 986
 987 /* Marks as router stream */
 988
 989 void silc_packet_stream_set_router(SilcPacketStream stream)
 990 {
 991   stream->is_router = TRUE;
 992 }
 993
 994 /* Mark to include IV in ciphertext */
 995
 996 void silc_packet_stream_set_iv_included(SilcPacketStream stream)
 997 {
 998   stream->iv_included = TRUE;
 999 }
1000
1001 /* Links `callbacks' to `stream' for specified packet types */
1002
1003 static SilcBool silc_packet_stream_link_va(SilcPacketStream stream,
1004                                            SilcPacketCallbacks *callbacks,
1005                                            void *callback_context,
1006                                            int priority, va_list ap)
1007 {
1008   SilcPacketProcess p, e;
1009   SilcInt32 packet_type;
1010   int i;
1011
1012   SILC_LOG_DEBUG(("Linking callbacks %p to stream %p", callbacks, stream));
1013
1014   if (!callbacks)
1015     return FALSE;
1016   if (!callbacks->packet_receive)
1017     return FALSE;
1018
1019   p = silc_calloc(1, sizeof(*p));
1020   if (!p)
1021     return FALSE;
1022
1023   p->priority = priority;
1024   p->callbacks = callbacks;
1025   p->callback_context = callback_context;
1026
1027   silc_mutex_lock(stream->lock);
1028
1029   if (!stream->process) {
1030     stream->process = silc_dlist_init();
1031     if (!stream->process) {
1032       silc_mutex_unlock(stream->lock);
1033       silc_free(p);
1034       return FALSE;
1035     }
1036   }
1037
1038   /* According to priority set the procesor to correct position.  First
1039      entry has the highest priority */
1040   silc_dlist_start(stream->process);
1041   while ((e = silc_dlist_get(stream->process)) != SILC_LIST_END) {
1042     if (p->priority > e->priority) {
1043       silc_dlist_insert(stream->process, p);
1044       break;
1045     }
1046   }
1047   if (!e)
1048     silc_dlist_add(stream->process, p);
1049
1050   /* Get packet types to process */
1051   i = 1;
1052   while (1) {
1053     packet_type = va_arg(ap, SilcInt32);
1054
1055     if (packet_type == SILC_PACKET_ANY)
1056       break;
1057
1058     if (packet_type == -1)
1059       break;
1060
1061     p->types = silc_realloc(p->types, sizeof(*p->types) * (i + 1));
1062     if (!p->types) {
1063       silc_mutex_unlock(stream->lock);
1064       return FALSE;
1065     }
1066
1067     p->types[i - 1] = (SilcPacketType)packet_type;
1068     i++;
1069   }
1070   if (p->types)
1071     p->types[i - 1] = 0;
1072
1073   silc_mutex_unlock(stream->lock);
1074
1075   silc_packet_stream_ref(stream);
1076
1077   return TRUE;
1078 }
1079
1080 /* Links `callbacks' to `stream' for specified packet types */
1081
1082 SilcBool silc_packet_stream_link(SilcPacketStream stream,
1083                                  SilcPacketCallbacks *callbacks,
1084                                  void *callback_context,
1085                                  int priority, ...)
1086 {
1087   va_list ap;
1088   SilcBool ret;
1089
1090   va_start(ap, priority);
1091   ret = silc_packet_stream_link_va(stream, callbacks, callback_context,
1092                                    priority, ap);
1093   va_end(ap);
1094
1095   return ret;
1096 }
1097
1098 /* Unlinks `callbacks' from `stream'. */
1099
1100 void silc_packet_stream_unlink(SilcPacketStream stream,
1101                                SilcPacketCallbacks *callbacks,
1102                                void *callback_context)
1103 {
1104   SilcPacketProcess p;
1105
1106   SILC_LOG_DEBUG(("Unlinking callbacks %p from stream %p",
1107                   callbacks, stream));
1108
1109   silc_mutex_lock(stream->lock);
1110
1111   silc_dlist_start(stream->process);
1112   while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END)
1113     if (p->callbacks == callbacks &&
1114         p->callback_context == callback_context) {
1115       silc_dlist_del(stream->process, p);
1116       silc_free(p->types);
1117       silc_free(p);
1118       break;
1119     }
1120
1121   if (!silc_dlist_count(stream->process)) {
1122     silc_dlist_uninit(stream->process);
1123     stream->process = NULL;
1124   }
1125
1126   silc_mutex_unlock(stream->lock);
1127
1128   silc_packet_stream_unref(stream);
1129 }
1130
1131 /* Returns TRUE if stream is UDP stream */
1132
1133 SilcBool silc_packet_stream_is_udp(SilcPacketStream stream)
1134 {
1135   return stream->udp || silc_socket_stream_is_udp(stream->stream, NULL);
1136 }
1137
1138 /* Return packet sender IP and port for UDP packet stream */
1139
1140 SilcBool silc_packet_get_sender(SilcPacket packet,
1141                                 const char **sender_ip,
1142                                 SilcUInt16 *sender_port)
1143 {
1144   if (!packet->stream->remote_udp)
1145     return FALSE;
1146
1147   *sender_ip = packet->stream->remote_udp->remote_ip;
1148   *sender_port = packet->stream->remote_udp->remote_port;
1149
1150   return TRUE;
1151 }
1152
1153 /* Reference packet stream */
1154
1155 void silc_packet_stream_ref(SilcPacketStream stream)
1156 {
1157   silc_atomic_add_int32(&stream->refcnt, 1);
1158   SILC_LOG_DEBUG(("Stream %p, refcnt %d->%d", stream,
1159                   silc_atomic_get_int32(&stream->refcnt) - 1,
1160                   silc_atomic_get_int32(&stream->refcnt)));
1161 }
1162
1163 /* Unreference packet stream */
1164
1165 void silc_packet_stream_unref(SilcPacketStream stream)
1166 {
1167   SILC_LOG_DEBUG(("Stream %p, refcnt %d->%d", stream,
1168                   silc_atomic_get_int32(&stream->refcnt),
1169                   silc_atomic_get_int32(&stream->refcnt) - 1));
1170   if (silc_atomic_sub_int32(&stream->refcnt, 1) > 0)
1171     return;
1172   silc_atomic_add_int32(&stream->refcnt, 1);
1173   silc_packet_stream_destroy(stream);
1174 }
1175
1176 /* Return engine */
1177
1178 SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream)
1179 {
1180   return stream->sc->engine;
1181 }
1182
1183 /* Set application context for packet stream */
1184
1185 void silc_packet_set_context(SilcPacketStream stream, void *stream_context)
1186 {
1187   silc_mutex_lock(stream->lock);
1188   stream->stream_context = stream_context;
1189   silc_mutex_unlock(stream->lock);
1190 }
1191
1192 /* Return application context from packet stream */
1193
1194 void *silc_packet_get_context(SilcPacketStream stream)
1195 {
1196   void *context;
1197   silc_mutex_lock(stream->lock);
1198   context = stream->stream_context;
1199   silc_mutex_unlock(stream->lock);
1200   return context;
1201 }
1202
1203 /* Change underlaying stream */
1204
1205 void silc_packet_stream_set_stream(SilcPacketStream ps,
1206                                    SilcStream stream)
1207 {
1208   if (ps->stream)
1209     silc_stream_set_notifier(ps->stream, ps->sc->schedule, NULL, NULL);
1210   ps->stream = stream;
1211   silc_stream_set_notifier(ps->stream, ps->sc->schedule, silc_packet_stream_io,
1212                            ps);
1213 }
1214
1215 /* Return underlaying stream */
1216
1217 SilcStream silc_packet_stream_get_stream(SilcPacketStream stream)
1218 {
1219   return stream->stream;
1220 }
1221
1222 /* Set keys. */
1223
1224 SilcBool silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
1225                               SilcCipher receive_key, SilcHmac send_hmac,
1226                               SilcHmac receive_hmac, SilcBool rekey)
1227 {
1228   SILC_LOG_DEBUG(("Setting new keys to packet stream %p", stream));
1229
1230   /* If doing rekey, send REKEY_DONE packet */
1231   if (rekey) {
1232     /* This will take stream lock. */
1233     if (!silc_packet_send_raw(stream, SILC_PACKET_REKEY_DONE, 0,
1234                               stream->src_id_type, stream->src_id,
1235                               stream->src_id_len, stream->dst_id_type,
1236                               stream->dst_id, stream->dst_id_len,
1237                               NULL, 0, stream->send_key[0],
1238                               stream->send_hmac[0]))
1239       return FALSE;
1240
1241     /* Write the packet to the stream */
1242     if (!silc_packet_stream_write(stream, TRUE))
1243       return FALSE;
1244   } else {
1245     silc_mutex_lock(stream->lock);
1246   }
1247
1248   /* In case IV Included is set, save the old keys */
1249   if (stream->iv_included) {
1250     if (stream->send_key[1] && send_key) {
1251       silc_cipher_free(stream->send_key[1]);
1252       stream->send_key[1] = stream->send_key[0];
1253     }
1254     if (stream->receive_key[1] && receive_key) {
1255       silc_cipher_free(stream->receive_key[1]);
1256       stream->receive_key[1] = stream->receive_key[0];
1257     }
1258     if (stream->send_hmac[1] && send_hmac) {
1259       silc_hmac_free(stream->send_hmac[1]);
1260       stream->send_hmac[1] = stream->send_hmac[0];
1261     }
1262     if (stream->receive_hmac[1] && receive_hmac) {
1263       silc_hmac_free(stream->receive_hmac[1]);
1264       stream->receive_hmac[1] = stream->receive_hmac[0];
1265     }
1266   } else {
1267     if (stream->send_key[0] && send_key)
1268       silc_cipher_free(stream->send_key[0]);
1269     if (stream->receive_key[0] && receive_key)
1270       silc_cipher_free(stream->receive_key[0]);
1271     if (stream->send_hmac[0] && send_hmac)
1272       silc_hmac_free(stream->send_hmac[0]);
1273     if (stream->receive_hmac[0] && receive_hmac)
1274       silc_hmac_free(stream->receive_hmac[0]);
1275   }
1276
1277   /* Set keys */
1278   if (send_key)
1279     stream->send_key[0] = send_key;
1280   if (receive_key)
1281     stream->receive_key[0] = receive_key;
1282   if (send_hmac)
1283     stream->send_hmac[0] = send_hmac;
1284   if (receive_hmac)
1285     stream->receive_hmac[0] = receive_hmac;
1286
1287   silc_mutex_unlock(stream->lock);
1288   return TRUE;
1289 }
1290
1291 /* Return current ciphers from packet stream */
1292
1293 SilcBool silc_packet_get_keys(SilcPacketStream stream,
1294                               SilcCipher *send_key,
1295                               SilcCipher *receive_key,
1296                               SilcHmac *send_hmac,
1297                               SilcHmac *receive_hmac)
1298 {
1299   if (!stream->send_key[0] && !stream->receive_key[0] &&
1300       !stream->send_hmac[0] && !stream->receive_hmac[0])
1301     return FALSE;
1302
1303   silc_mutex_lock(stream->lock);
1304
1305   if (send_key)
1306     *send_key = stream->send_key[0];
1307   if (receive_key)
1308     *receive_key = stream->receive_key[0];
1309   if (send_hmac)
1310     *send_hmac = stream->send_hmac[0];
1311   if (receive_hmac)
1312     *receive_hmac = stream->receive_hmac[0];
1313
1314   silc_mutex_unlock(stream->lock);
1315
1316   return TRUE;
1317 }
1318
1319 /* Set SILC IDs to packet stream */
1320
1321 SilcBool silc_packet_set_ids(SilcPacketStream stream,
1322                              SilcIdType src_id_type, const void *src_id,
1323                              SilcIdType dst_id_type, const void *dst_id)
1324 {
1325   SilcUInt32 len;
1326   unsigned char tmp[32];
1327
1328   if (!src_id && !dst_id)
1329     return FALSE;
1330
1331   silc_mutex_lock(stream->lock);
1332
1333   if (src_id) {
1334     SILC_LOG_DEBUG(("Setting source ID to packet stream %p", stream));
1335
1336     silc_free(stream->src_id);
1337     stream->src_id = NULL;
1338     if (!silc_id_id2str(src_id, src_id_type, tmp, sizeof(tmp), &len)) {
1339       silc_mutex_unlock(stream->lock);
1340       return FALSE;
1341     }
1342     stream->src_id = silc_memdup(tmp, len);
1343     if (!stream->src_id) {
1344       silc_mutex_unlock(stream->lock);
1345       return FALSE;
1346     }
1347     stream->src_id_type = src_id_type;
1348     stream->src_id_len = len;
1349   }
1350
1351   if (dst_id) {
1352     SILC_LOG_DEBUG(("Setting destination ID to packet stream %p", stream));
1353
1354     silc_free(stream->dst_id);
1355     stream->dst_id = NULL;
1356     if (!silc_id_id2str(dst_id, dst_id_type, tmp, sizeof(tmp), &len)) {
1357       silc_mutex_unlock(stream->lock);
1358       return FALSE;
1359     }
1360     stream->dst_id = silc_memdup(tmp, len);
1361     if (!stream->dst_id) {
1362       silc_mutex_unlock(stream->lock);
1363       return FALSE;
1364     }
1365     stream->dst_id_type = dst_id_type;
1366     stream->dst_id_len = len;
1367   }
1368
1369   silc_mutex_unlock(stream->lock);
1370
1371   return TRUE;
1372 }
1373
1374 /* Return IDs from the packet stream */
1375
1376 SilcBool silc_packet_get_ids(SilcPacketStream stream,
1377                              SilcBool *src_id_set, SilcID *src_id,
1378                              SilcBool *dst_id_set, SilcID *dst_id)
1379 {
1380   if (src_id && stream->src_id)
1381     if (!silc_id_str2id2(stream->src_id, stream->src_id_len,
1382                          stream->src_id_type, src_id))
1383       return FALSE;
1384
1385   if (stream->src_id && src_id_set)
1386     *src_id_set = TRUE;
1387
1388   if (dst_id && stream->dst_id)
1389     if (!silc_id_str2id2(stream->dst_id, stream->dst_id_len,
1390                          stream->dst_id_type, dst_id))
1391       return FALSE;
1392
1393   if (stream->dst_id && dst_id_set)
1394     *dst_id_set = TRUE;
1395
1396   return TRUE;
1397 }
1398
1399 /* Adds Security ID (SID) */
1400
1401 SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid)
1402 {
1403   if (!stream->iv_included)
1404     return FALSE;
1405
1406   SILC_LOG_DEBUG(("Set packet stream %p SID to %d", stream, sid));
1407
1408   stream->sid = sid;
1409   return TRUE;
1410 }
1411
1412 /* Free packet */
1413
1414 void silc_packet_free(SilcPacket packet)
1415 {
1416   SilcPacketStream stream = packet->stream;
1417
1418   SILC_LOG_DEBUG(("Freeing packet %p", packet));
1419
1420   /* Check for double free */
1421   SILC_ASSERT(packet->stream != NULL);
1422
1423   packet->stream = NULL;
1424   packet->src_id = packet->dst_id = NULL;
1425   silc_buffer_reset(&packet->buffer);
1426
1427   silc_mutex_lock(stream->sc->engine->lock);
1428
1429   /* Put the packet back to freelist */
1430   silc_list_add(stream->sc->engine->packet_pool, packet);
1431   if (silc_list_count(stream->sc->engine->packet_pool) == 1)
1432     silc_list_start(stream->sc->engine->packet_pool);
1433
1434   silc_mutex_unlock(stream->sc->engine->lock);
1435 }
1436
1437 /****************************** Packet Sending ******************************/
1438
1439 /* Prepare outgoing data buffer for packet sending.  Returns the
1440    pointer to that buffer into the `packet'. */
1441
1442 static inline SilcBool silc_packet_send_prepare(SilcPacketStream stream,
1443                                                 SilcUInt32 totlen,
1444                                                 SilcHmac hmac,
1445                                                 SilcBuffer packet)
1446 {
1447   unsigned char *oldptr;
1448   unsigned int mac_len = hmac ? silc_hmac_len(hmac) : 0;
1449
1450   totlen += mac_len;
1451
1452   /* Allocate more space if needed */
1453   if (silc_unlikely(silc_buffer_taillen(&stream->outbuf) < totlen)) {
1454     if (!silc_buffer_realloc(&stream->outbuf,
1455                              silc_buffer_truelen(&stream->outbuf) + totlen))
1456       return FALSE;
1457   }
1458
1459   /* Pull data area for the new packet, and return pointer to the start of
1460      the data area and save the pointer in to the `packet'.  MAC is pulled
1461      later after it's computed. */
1462   oldptr = silc_buffer_pull_tail(&stream->outbuf, totlen);
1463   silc_buffer_set(packet, oldptr, totlen);
1464   silc_buffer_push_tail(packet, mac_len);
1465
1466   return TRUE;
1467 }
1468
1469 /* Increments counter when encrypting in counter mode. */
1470
1471 static inline void silc_packet_send_ctr_increment(SilcPacketStream stream,
1472                                                   SilcCipher cipher,
1473                                                   unsigned char *ret_iv)
1474 {
1475   unsigned char *iv = silc_cipher_get_iv(cipher);
1476   SilcUInt32 pc1, pc2;
1477
1478   /* Reset block counter */
1479   memset(iv + 12, 0, 4);
1480
1481   /* If IV Included flag, return the 64-bit IV for inclusion in packet */
1482   if (stream->iv_included) {
1483     /* Get new nonce */
1484     ret_iv[0] = silc_rng_get_byte_fast(stream->sc->engine->rng);
1485     ret_iv[1] = ret_iv[0] + iv[4];
1486     ret_iv[2] = ret_iv[0] ^ ret_iv[1];
1487     ret_iv[3] = ret_iv[0] + ret_iv[2];
1488
1489     /* Increment 32-bit packet counter */
1490     SILC_GET32_MSB(pc1, iv + 8);
1491     pc1++;
1492     SILC_PUT32_MSB(pc1, ret_iv + 4);
1493
1494     SILC_LOG_HEXDUMP(("IV"), ret_iv, 8);
1495
1496     /* Set new nonce to counter block */
1497     memcpy(iv + 4, ret_iv, 8);
1498   } else {
1499     /* Increment 64-bit packet counter */
1500     SILC_GET32_MSB(pc1, iv + 4);
1501     SILC_GET32_MSB(pc2, iv + 8);
1502     if (++pc2 == 0)
1503       ++pc1;
1504     SILC_PUT32_MSB(pc1, iv + 4);
1505     SILC_PUT32_MSB(pc2, iv + 8);
1506   }
1507
1508   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
1509 }
1510
1511 /* Internal routine to assemble outgoing packet.  Assembles and encryptes
1512    the packet.  The silc_packet_stream_write needs to be called to send it
1513    after this returns TRUE. */
1514
1515 static inline SilcBool silc_packet_send_raw(SilcPacketStream stream,
1516                                             SilcPacketType type,
1517                                             SilcPacketFlags flags,
1518                                             SilcIdType src_id_type,
1519                                             unsigned char *src_id,
1520                                             SilcUInt32 src_id_len,
1521                                             SilcIdType dst_id_type,
1522                                             unsigned char *dst_id,
1523                                             SilcUInt32 dst_id_len,
1524                                             const unsigned char *data,
1525                                             SilcUInt32 data_len,
1526                                             SilcCipher cipher,
1527                                             SilcHmac hmac)
1528 {
1529   unsigned char tmppad[SILC_PACKET_MAX_PADLEN], iv[33], psn[4];
1530   int block_len = (cipher ? silc_cipher_get_block_len(cipher) : 0);
1531   int i, enclen, truelen, padlen = 0, ivlen = 0, psnlen = 0;
1532   SilcBool ctr;
1533   SilcBufferStruct packet;
1534
1535   SILC_LOG_DEBUG(("Sending packet %s (%d) flags %d, src %d dst %d, "
1536                   "data len %d", silc_get_packet_name(type), stream->send_psn,
1537                   flags, src_id_type, dst_id_type, data_len));
1538
1539   /* Get the true length of the packet. This is saved as payload length
1540      into the packet header.  This does not include the length of the
1541      padding. */
1542   data_len = SILC_PACKET_DATALEN(data_len, (SILC_PACKET_HEADER_LEN +
1543                                             src_id_len + dst_id_len));
1544   enclen = truelen = (data_len + SILC_PACKET_HEADER_LEN +
1545                       src_id_len + dst_id_len);
1546
1547   /* If using CTR mode, increment the counter */
1548   ctr = (cipher && silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR);
1549   if (ctr) {
1550     silc_packet_send_ctr_increment(stream, cipher, iv + 1);
1551
1552     /* If IV is included, the SID, IV and sequence number is added to packet */
1553     if (stream->iv_included && cipher) {
1554       psnlen = sizeof(psn);
1555       ivlen = 8 + 1;
1556       iv[0] = stream->sid;
1557     }
1558   } else {
1559     /* If IV is included, the SID, IV and sequence number is added to packet */
1560     if (stream->iv_included && cipher) {
1561       psnlen = sizeof(psn);
1562       ivlen = block_len + 1;
1563       iv[0] = stream->sid;
1564       memcpy(iv + 1, silc_cipher_get_iv(cipher), block_len);
1565     }
1566   }
1567
1568   /* We automatically figure out the packet structure from the packet
1569      type and flags, and calculate correct length.  Private messages with
1570      private keys and channel messages are special packets as their
1571      payload is encrypted already. */
1572   if (type == SILC_PACKET_PRIVATE_MESSAGE &&
1573       flags & SILC_PACKET_FLAG_PRIVMSG_KEY) {
1574     /* Padding is calculated from header + IDs */
1575     if (!ctr)
1576       SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1577                           psnlen), block_len, padlen);
1578
1579     /* Length to encrypt, header + IDs + padding. */
1580     enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1581               padlen + psnlen);
1582
1583   } else if (type == SILC_PACKET_CHANNEL_MESSAGE) {
1584     if (stream->sc->engine->local_is_router && stream->is_router) {
1585       /* Channel messages between routers are encrypted as normal packets.
1586          Padding is calculated from true length of the packet. */
1587       if (!ctr)
1588         SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
1589
1590       enclen += padlen + psnlen;
1591     } else {
1592       /* Padding is calculated from header + IDs */
1593       if (!ctr)
1594         SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1595                             psnlen), block_len, padlen);
1596
1597       /* Length to encrypt, header + IDs + padding. */
1598       enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1599                 padlen + psnlen);
1600     }
1601   } else {
1602     /* Padding is calculated from true length of the packet */
1603     if (flags & SILC_PACKET_FLAG_LONG_PAD)
1604       SILC_PACKET_PADLEN_MAX(truelen + psnlen, block_len, padlen);
1605     else if (!ctr)
1606       SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
1607
1608     enclen += padlen + psnlen;
1609   }
1610
1611   /* Remove implementation specific flags */
1612   flags &= ~(SILC_PACKET_FLAG_LONG_PAD);
1613
1614   /* Get random padding */
1615   for (i = 0; i < padlen; i++) tmppad[i] =
1616     silc_rng_get_byte_fast(stream->sc->engine->rng);
1617
1618   silc_mutex_lock(stream->lock);
1619
1620   /* Get packet pointer from the outgoing buffer */
1621   if (silc_unlikely(!silc_packet_send_prepare(stream, truelen + padlen + ivlen
1622                                               + psnlen, hmac, &packet))) {
1623     silc_mutex_unlock(stream->lock);
1624     return FALSE;
1625   }
1626
1627   SILC_PUT32_MSB(stream->send_psn, psn);
1628
1629   /* Create the packet.  This creates the SILC header, adds padding, and
1630      the actual packet data. */
1631   i = silc_buffer_format(&packet,
1632                          SILC_STR_DATA(iv, ivlen),
1633                          SILC_STR_DATA(psn, psnlen),
1634                          SILC_STR_UI_SHORT(truelen),
1635                          SILC_STR_UI_CHAR(flags),
1636                          SILC_STR_UI_CHAR(type),
1637                          SILC_STR_UI_CHAR(padlen),
1638                          SILC_STR_UI_CHAR(0),
1639                          SILC_STR_UI_CHAR(src_id_len),
1640                          SILC_STR_UI_CHAR(dst_id_len),
1641                          SILC_STR_UI_CHAR(src_id_type),
1642                          SILC_STR_DATA(src_id, src_id_len),
1643                          SILC_STR_UI_CHAR(dst_id_type),
1644                          SILC_STR_DATA(dst_id, dst_id_len),
1645                          SILC_STR_DATA(tmppad, padlen),
1646                          SILC_STR_DATA(data, data_len),
1647                          SILC_STR_END);
1648   if (silc_unlikely(i < 0)) {
1649     silc_mutex_unlock(stream->lock);
1650     return FALSE;
1651   }
1652
1653   SILC_LOG_HEXDUMP(("Assembled packet, len %d", silc_buffer_len(&packet)),
1654                    silc_buffer_data(&packet), silc_buffer_len(&packet));
1655
1656   /* Encrypt the packet */
1657   if (silc_likely(cipher)) {
1658     SILC_LOG_DEBUG(("Encrypting packet"));
1659     silc_cipher_set_iv(cipher, NULL);
1660     if (silc_unlikely(!silc_cipher_encrypt(cipher, packet.data + ivlen,
1661                                            packet.data + ivlen, enclen,
1662                                            NULL))) {
1663       SILC_LOG_ERROR(("Packet encryption failed"));
1664       silc_mutex_unlock(stream->lock);
1665       return FALSE;
1666     }
1667   }
1668
1669   /* Compute HMAC */
1670   if (silc_likely(hmac)) {
1671     SilcUInt32 mac_len;
1672
1673     /* MAC is computed from the entire encrypted packet data, and put
1674        to the end of the packet. */
1675     silc_hmac_init(hmac);
1676     silc_hmac_update(hmac, psn, sizeof(psn));
1677     silc_hmac_update(hmac, packet.data, silc_buffer_len(&packet));
1678     silc_hmac_final(hmac, packet.tail, &mac_len);
1679     silc_buffer_pull_tail(&packet, mac_len);
1680     stream->send_psn++;
1681   }
1682
1683   return TRUE;
1684 }
1685
1686 /* Sends a packet */
1687
1688 SilcBool silc_packet_send(SilcPacketStream stream,
1689                           SilcPacketType type, SilcPacketFlags flags,
1690                           const unsigned char *data, SilcUInt32 data_len)
1691 {
1692   SilcBool ret;
1693
1694   ret = silc_packet_send_raw(stream, type, flags,
1695                              stream->src_id_type,
1696                              stream->src_id,
1697                              stream->src_id_len,
1698                              stream->dst_id_type,
1699                              stream->dst_id,
1700                              stream->dst_id_len,
1701                              data, data_len,
1702                              stream->send_key[0],
1703                              stream->send_hmac[0]);
1704
1705   /* Write the packet to the stream */
1706   return ret ? silc_packet_stream_write(stream, FALSE) : FALSE;
1707 }
1708
1709 /* Sends a packet, extended routine */
1710
1711 SilcBool silc_packet_send_ext(SilcPacketStream stream,
1712                               SilcPacketType type, SilcPacketFlags flags,
1713                               SilcIdType src_id_type, void *src_id,
1714                               SilcIdType dst_id_type, void *dst_id,
1715                               const unsigned char *data, SilcUInt32 data_len,
1716                               SilcCipher cipher, SilcHmac hmac)
1717 {
1718   unsigned char src_id_data[32], dst_id_data[32];
1719   SilcUInt32 src_id_len, dst_id_len;
1720   SilcBool ret;
1721
1722   if (src_id)
1723     if (!silc_id_id2str(src_id, src_id_type, src_id_data,
1724                         sizeof(src_id_data), &src_id_len))
1725       return FALSE;
1726   if (dst_id)
1727     if (!silc_id_id2str(dst_id, dst_id_type, dst_id_data,
1728                         sizeof(dst_id_data), &dst_id_len))
1729       return FALSE;
1730
1731   ret = silc_packet_send_raw(stream, type, flags,
1732                              src_id ? src_id_type : stream->src_id_type,
1733                              src_id ? src_id_data : stream->src_id,
1734                              src_id ? src_id_len : stream->src_id_len,
1735                              dst_id ? dst_id_type : stream->dst_id_type,
1736                              dst_id ? dst_id_data : stream->dst_id,
1737                              dst_id ? dst_id_len : stream->dst_id_len,
1738                              data, data_len,
1739                              cipher ? cipher : stream->send_key[0],
1740                              hmac ? hmac : stream->send_hmac[0]);
1741
1742   /* Write the packet to the stream */
1743   return ret ? silc_packet_stream_write(stream, FALSE) : FALSE;
1744 }
1745
1746 /* Sends packet after formatting the arguments to buffer */
1747
1748 SilcBool silc_packet_send_va(SilcPacketStream stream,
1749                              SilcPacketType type, SilcPacketFlags flags, ...)
1750 {
1751   SilcBufferStruct buf;
1752   SilcBool ret;
1753   va_list va;
1754
1755   va_start(va, flags);
1756
1757   memset(&buf, 0, sizeof(buf));
1758   if (silc_buffer_format_vp(&buf, va) < 0) {
1759     va_end(va);
1760     return FALSE;
1761   }
1762
1763   ret = silc_packet_send(stream, type, flags, silc_buffer_data(&buf),
1764                          silc_buffer_len(&buf));
1765
1766   silc_buffer_purge(&buf);
1767   va_end(va);
1768
1769   return ret;
1770 }
1771
1772 /* Sends packet after formatting the arguments to buffer, extended routine */
1773
1774 SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
1775                                  SilcPacketType type, SilcPacketFlags flags,
1776                                  SilcIdType src_id_type, void *src_id,
1777                                  SilcIdType dst_id_type, void *dst_id,
1778                                  SilcCipher cipher, SilcHmac hmac, ...)
1779 {
1780   SilcBufferStruct buf;
1781   SilcBool ret;
1782   va_list va;
1783
1784   va_start(va, hmac);
1785
1786   memset(&buf, 0, sizeof(buf));
1787   if (silc_buffer_format_vp(&buf, va) < 0) {
1788     va_end(va);
1789     return FALSE;
1790   }
1791
1792   ret = silc_packet_send_ext(stream, type, flags, src_id_type, src_id,
1793                              dst_id_type, dst_id, silc_buffer_data(&buf),
1794                              silc_buffer_len(&buf), cipher, hmac);
1795
1796   silc_buffer_purge(&buf);
1797   va_end(va);
1798
1799   return TRUE;
1800 }
1801
1802 /***************************** Packet Receiving *****************************/
1803
1804 /* Checks MAC in the packet. Returns TRUE if MAC is Ok. */
1805
1806 static inline SilcBool silc_packet_check_mac(SilcHmac hmac,
1807                                              const unsigned char *data,
1808                                              SilcUInt32 data_len,
1809                                              const unsigned char *packet_mac,
1810                                              const unsigned char *packet_seq,
1811                                              SilcUInt32 sequence)
1812 {
1813   /* Check MAC */
1814   if (silc_likely(hmac)) {
1815     unsigned char mac[32], psn[4];
1816     SilcUInt32 mac_len;
1817
1818     SILC_LOG_DEBUG(("Verifying MAC"));
1819
1820     /* Compute HMAC of packet */
1821     silc_hmac_init(hmac);
1822
1823     if (!packet_seq) {
1824       SILC_PUT32_MSB(sequence, psn);
1825       silc_hmac_update(hmac, psn, 4);
1826     } else
1827       silc_hmac_update(hmac, packet_seq, 4);
1828
1829     silc_hmac_update(hmac, data, data_len);
1830     silc_hmac_final(hmac, mac, &mac_len);
1831
1832     /* Compare the MAC's */
1833     if (silc_unlikely(memcmp(packet_mac, mac, mac_len))) {
1834       SILC_LOG_DEBUG(("MAC failed"));
1835       return FALSE;
1836     }
1837
1838     SILC_LOG_DEBUG(("MAC is Ok"));
1839   }
1840
1841   return TRUE;
1842 }
1843
1844 /* Increments/sets counter when decrypting in counter mode. */
1845
1846 static inline void silc_packet_receive_ctr_increment(SilcPacketStream stream,
1847                                                      unsigned char *iv,
1848                                                      unsigned char *packet_iv)
1849 {
1850   SilcUInt32 pc1, pc2;
1851
1852   /* If IV Included flag, set the IV from packet to block counter. */
1853   if (stream->iv_included) {
1854     memcpy(iv + 4, packet_iv, 8);
1855   } else {
1856     /* Increment 64-bit packet counter. */
1857     SILC_GET32_MSB(pc1, iv + 4);
1858     SILC_GET32_MSB(pc2, iv + 8);
1859     if (++pc2 == 0)
1860       ++pc1;
1861     SILC_PUT32_MSB(pc1, iv + 4);
1862     SILC_PUT32_MSB(pc2, iv + 8);
1863   }
1864
1865   /* Reset block counter */
1866   memset(iv + 12, 0, 4);
1867
1868   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
1869 }
1870
1871 /* Decrypts SILC packet.  Handles both normal and special packet decryption.
1872    Return 0 when packet is normal and 1 when it it special, -1 on error. */
1873
1874 static inline int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
1875                                       SilcUInt32 sequence, SilcBuffer buffer,
1876                                       SilcBool normal)
1877 {
1878   if (normal == TRUE) {
1879     if (silc_likely(cipher)) {
1880       /* Decrypt rest of the packet */
1881       SILC_LOG_DEBUG(("Decrypting the packet"));
1882       if (silc_unlikely(!silc_cipher_decrypt(cipher, buffer->data,
1883                                              buffer->data,
1884                                              silc_buffer_len(buffer), NULL)))
1885         return -1;
1886     }
1887     return 0;
1888
1889   } else {
1890     /* Decrypt rest of the header plus padding */
1891     if (silc_likely(cipher)) {
1892       SilcUInt16 len;
1893       SilcUInt32 block_len = silc_cipher_get_block_len(cipher);
1894
1895       SILC_LOG_DEBUG(("Decrypting the header"));
1896
1897       /* Padding length + src id len + dst id len + header length - 16
1898          bytes already decrypted, gives the rest of the encrypted packet */
1899       silc_buffer_push(buffer, block_len);
1900       len = (((SilcUInt8)buffer->data[4] + (SilcUInt8)buffer->data[6] +
1901               (SilcUInt8)buffer->data[7] + SILC_PACKET_HEADER_LEN) -
1902              block_len);
1903       silc_buffer_pull(buffer, block_len);
1904
1905       if (silc_unlikely(len > silc_buffer_len(buffer))) {
1906         SILC_LOG_ERROR(("Garbage in header of packet, bad packet length, "
1907                         "packet dropped"));
1908         return -1;
1909       }
1910       if (silc_unlikely(!silc_cipher_decrypt(cipher, buffer->data,
1911                                              buffer->data, len, NULL)))
1912         return -1;
1913     }
1914
1915     return 1;
1916   }
1917 }
1918
1919 /* Parses the packet. This is called when a whole packet is ready to be
1920    parsed. The buffer sent must be already decrypted before calling this
1921    function. */
1922
1923 static inline SilcBool silc_packet_parse(SilcPacket packet)
1924 {
1925   SilcBuffer buffer = &packet->buffer;
1926   SilcUInt8 padlen = (SilcUInt8)buffer->data[4];
1927   SilcUInt8 src_id_len, dst_id_len, src_id_type, dst_id_type;
1928   int ret;
1929
1930   SILC_LOG_DEBUG(("Parsing incoming packet"));
1931
1932   /* Parse the buffer.  This parses the SILC header of the packet. */
1933   ret = silc_buffer_unformat(buffer,
1934                              SILC_STR_ADVANCE,
1935                              SILC_STR_OFFSET(6),
1936                              SILC_STR_UI_CHAR(&src_id_len),
1937                              SILC_STR_UI_CHAR(&dst_id_len),
1938                              SILC_STR_UI_CHAR(&src_id_type),
1939                              SILC_STR_END);
1940   if (silc_unlikely(ret == -1)) {
1941     if (!packet->stream->udp &&
1942         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1943       SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
1944     return FALSE;
1945   }
1946
1947   if (silc_unlikely(src_id_len > SILC_PACKET_MAX_ID_LEN ||
1948                     dst_id_len > SILC_PACKET_MAX_ID_LEN)) {
1949     if (!packet->stream->udp &&
1950         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1951       SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
1952                       packet->src_id_len, packet->dst_id_len));
1953     return FALSE;
1954   }
1955
1956   ret = silc_buffer_unformat(buffer,
1957                              SILC_STR_ADVANCE,
1958                              SILC_STR_DATA(&packet->src_id, src_id_len),
1959                              SILC_STR_UI_CHAR(&dst_id_type),
1960                              SILC_STR_DATA(&packet->dst_id, dst_id_len),
1961                              SILC_STR_OFFSET(padlen),
1962                              SILC_STR_END);
1963   if (silc_unlikely(ret == -1)) {
1964     if (!packet->stream->udp &&
1965         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1966       SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
1967     return FALSE;
1968   }
1969
1970   if (silc_unlikely(src_id_type > SILC_ID_CHANNEL ||
1971                     dst_id_type > SILC_ID_CHANNEL)) {
1972     if (!packet->stream->udp &&
1973         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1974       SILC_LOG_ERROR(("Bad ID types in packet (%d and %d)",
1975                       src_id_type, dst_id_type));
1976     return FALSE;
1977   }
1978
1979   packet->src_id_len = src_id_len;
1980   packet->dst_id_len = dst_id_len;
1981   packet->src_id_type = src_id_type;
1982   packet->dst_id_type = dst_id_type;
1983
1984   SILC_LOG_HEXDUMP(("Parsed packet, len %d", silc_buffer_headlen(buffer) +
1985                    silc_buffer_len(buffer)), buffer->head,
1986                    silc_buffer_headlen(buffer) + silc_buffer_len(buffer));
1987
1988   SILC_LOG_DEBUG(("Incoming packet type: %d (%s), flags %d", packet->type,
1989                   silc_get_packet_name(packet->type), packet->flags));
1990
1991   return TRUE;
1992 }
1993
1994 /* Dispatch packet to application.  Called with stream->lock locked.
1995    Returns FALSE if the stream was destroyed while dispatching a packet. */
1996
1997 static SilcBool silc_packet_dispatch(SilcPacket packet)
1998 {
1999   SilcPacketStream stream = packet->stream;
2000   SilcPacketProcess p;
2001   SilcBool default_sent = FALSE;
2002   SilcPacketType *pt;
2003
2004   /* Dispatch packet to all packet processors that want it */
2005
2006   if (silc_likely(!stream->process)) {
2007     /* Send to default processor as no others exist */
2008     SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2009     silc_mutex_unlock(stream->lock);
2010     if (silc_unlikely(!stream->sc->engine->callbacks->
2011                       packet_receive(stream->sc->engine, stream, packet,
2012                                      stream->sc->engine->callback_context,
2013                                      stream->stream_context)))
2014       silc_packet_free(packet);
2015     silc_mutex_lock(stream->lock);
2016     return stream->destroyed == FALSE;
2017   }
2018
2019   silc_dlist_start(stream->process);
2020   while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END) {
2021
2022     /* If priority is 0 or less, we send to default processor first
2023        because default processor has 0 priority */
2024     if (!default_sent && p->priority <= 0) {
2025       SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2026       default_sent = TRUE;
2027       silc_mutex_unlock(stream->lock);
2028       if (stream->sc->engine->callbacks->
2029           packet_receive(stream->sc->engine, stream, packet,
2030                          stream->sc->engine->callback_context,
2031                          stream->stream_context)) {
2032         silc_mutex_lock(stream->lock);
2033         return stream->destroyed == FALSE;
2034       }
2035       silc_mutex_lock(stream->lock);
2036     }
2037
2038     /* Send to processor */
2039     if (!p->types) {
2040       /* Send all packet types */
2041       SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
2042       silc_mutex_unlock(stream->lock);
2043       if (p->callbacks->packet_receive(stream->sc->engine, stream, packet,
2044                                        p->callback_context,
2045                                        stream->stream_context)) {
2046         silc_mutex_lock(stream->lock);
2047         return stream->destroyed == FALSE;
2048       }
2049       silc_mutex_lock(stream->lock);
2050     } else {
2051       /* Send specific types */
2052       for (pt = p->types; *pt; pt++) {
2053         if (*pt != packet->type)
2054           continue;
2055         SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
2056         silc_mutex_unlock(stream->lock);
2057         if (p->callbacks->packet_receive(stream->sc->engine, stream, packet,
2058                                          p->callback_context,
2059                                          stream->stream_context)) {
2060           silc_mutex_lock(stream->lock);
2061           return stream->destroyed == FALSE;
2062         }
2063         silc_mutex_lock(stream->lock);
2064         break;
2065       }
2066     }
2067   }
2068
2069   if (!default_sent) {
2070     /* Send to default processor as it has not been sent yet */
2071     SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2072     silc_mutex_unlock(stream->lock);
2073     if (stream->sc->engine->callbacks->
2074         packet_receive(stream->sc->engine, stream, packet,
2075                        stream->sc->engine->callback_context,
2076                        stream->stream_context)) {
2077       silc_mutex_lock(stream->lock);
2078       return stream->destroyed == FALSE;
2079     }
2080     silc_mutex_lock(stream->lock);
2081   }
2082
2083   /* If we got here, no one wanted the packet, so drop it */
2084   silc_packet_free(packet);
2085   return stream->destroyed == FALSE;
2086 }
2087
2088 /* Process incoming data and parse packets.  Called with stream->lock
2089    locked. */
2090
2091 static void silc_packet_read_process(SilcPacketStream stream)
2092 {
2093   SilcBuffer inbuf;
2094   SilcCipher cipher;
2095   SilcHmac hmac;
2096   SilcPacket packet;
2097   SilcUInt8 sid;
2098   SilcUInt16 packetlen;
2099   SilcUInt32 paddedlen, mac_len, block_len, ivlen, psnlen;
2100   unsigned char tmp[SILC_PACKET_MIN_HEADER_LEN], *header;
2101   unsigned char iv[SILC_CIPHER_MAX_IV_SIZE], *packet_seq = NULL;
2102   SilcBool normal;
2103   int ret;
2104
2105   /* Get inbuf.  If there is already some data for this stream in the buffer
2106      we already have it.  Otherwise get the current one from list, it will
2107      include the data. */
2108   inbuf = stream->inbuf;
2109   if (!inbuf) {
2110     silc_dlist_start(stream->sc->inbufs);
2111     inbuf = silc_dlist_get(stream->sc->inbufs);
2112   }
2113
2114   /* Parse the packets from the data */
2115   while (silc_buffer_len(inbuf) > 0) {
2116     ivlen = psnlen = 0;
2117     cipher = stream->receive_key[0];
2118     hmac = stream->receive_hmac[0];
2119     normal = FALSE;
2120
2121     if (silc_unlikely(silc_buffer_len(inbuf) <
2122                       (stream->iv_included ? SILC_PACKET_MIN_HEADER_LEN_IV :
2123                        SILC_PACKET_MIN_HEADER_LEN))) {
2124       SILC_LOG_DEBUG(("Partial packet in queue, waiting for the rest"));
2125       silc_dlist_del(stream->sc->inbufs, inbuf);
2126       stream->inbuf = inbuf;
2127       return;
2128     }
2129
2130     if (silc_likely(hmac))
2131       mac_len = silc_hmac_len(hmac);
2132     else
2133       mac_len = 0;
2134
2135     /* Decrypt first block of the packet to get the length field out */
2136     if (silc_likely(cipher)) {
2137       block_len = silc_cipher_get_block_len(cipher);
2138
2139       if (stream->iv_included) {
2140         /* SID, IV and sequence number is included in the ciphertext */
2141         sid = (SilcUInt8)inbuf->data[0];
2142
2143         if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR) {
2144           /* Set the CTR mode IV from packet to counter block */
2145           memcpy(iv, silc_cipher_get_iv(cipher), block_len);
2146           silc_packet_receive_ctr_increment(stream, iv, inbuf->data + 1);
2147           ivlen = 8 + 1;
2148         } else {
2149           /* Get IV from packet */
2150           memcpy(iv, inbuf->data + 1, block_len);
2151           ivlen = block_len + 1;
2152         }
2153         psnlen = 4;
2154
2155         /* Check SID, and get correct decryption key */
2156         if (sid != stream->sid) {
2157           /* If SID is recent get the previous key and use it */
2158           if (sid > 0 && stream->sid > 0 && stream->sid - 1 == sid &&
2159               stream->receive_key[1] && !stream->receive_hmac[1]) {
2160             cipher = stream->receive_key[1];
2161             hmac = stream->receive_hmac[1];
2162           } else {
2163             /* The SID is unknown, drop rest of the data in buffer */
2164             SILC_LOG_DEBUG(("Unknown Security ID %d in packet, expected %d",
2165                             sid, stream->sid));
2166             silc_mutex_unlock(stream->lock);
2167             SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_UNKNOWN_SID);
2168             silc_mutex_lock(stream->lock);
2169             goto out;
2170           }
2171         }
2172       } else {
2173         memcpy(iv, silc_cipher_get_iv(cipher), block_len);
2174
2175         /* If using CTR mode, increment the counter */
2176         if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR)
2177           silc_packet_receive_ctr_increment(stream, iv, NULL);
2178       }
2179
2180       if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR)
2181         silc_cipher_set_iv(cipher, NULL);
2182       silc_cipher_decrypt(cipher, inbuf->data + ivlen, tmp, block_len, iv);
2183
2184       header = tmp;
2185       if (stream->iv_included) {
2186         /* Take sequence number from packet */
2187         packet_seq = header;
2188         header += 4;
2189       }
2190     } else {
2191       /* Unencrypted packet */
2192       block_len = SILC_PACKET_MIN_HEADER_LEN;
2193       header = inbuf->data;
2194     }
2195
2196     /* Get packet length and full packet length with padding */
2197     SILC_PACKET_LENGTH(header, packetlen, paddedlen);
2198
2199     /* Sanity checks */
2200     if (silc_unlikely(packetlen < SILC_PACKET_MIN_LEN)) {
2201       if (!stream->udp && !silc_socket_stream_is_udp(stream->stream, NULL))
2202         SILC_LOG_ERROR(("Received too short packet"));
2203       silc_mutex_unlock(stream->lock);
2204       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2205       silc_mutex_lock(stream->lock);
2206       memset(tmp, 0, sizeof(tmp));
2207       goto out;
2208     }
2209
2210     if (silc_buffer_len(inbuf) < paddedlen + ivlen + mac_len) {
2211       SILC_LOG_DEBUG(("Received partial packet, waiting for the rest "
2212                       "(%d bytes)",
2213                       paddedlen + mac_len - silc_buffer_len(inbuf)));
2214       memset(tmp, 0, sizeof(tmp));
2215       silc_dlist_del(stream->sc->inbufs, inbuf);
2216       stream->inbuf = inbuf;
2217       return;
2218     }
2219
2220     /* Check MAC of the packet */
2221     if (silc_unlikely(!silc_packet_check_mac(hmac, inbuf->data,
2222                                              paddedlen + ivlen,
2223                                              inbuf->data + ivlen +
2224                                              paddedlen, packet_seq,
2225                                              stream->receive_psn))) {
2226       silc_mutex_unlock(stream->lock);
2227       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MAC_FAILED);
2228       silc_mutex_lock(stream->lock);
2229       memset(tmp, 0, sizeof(tmp));
2230       goto out;
2231     }
2232
2233     /* Get packet */
2234     packet = silc_packet_alloc(stream->sc->engine);
2235     if (silc_unlikely(!packet)) {
2236       silc_mutex_unlock(stream->lock);
2237       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
2238       silc_mutex_lock(stream->lock);
2239       memset(tmp, 0, sizeof(tmp));
2240       goto out;
2241     }
2242     packet->stream = stream;
2243
2244     /* Allocate more space to packet buffer, if needed */
2245     if (silc_unlikely(silc_buffer_truelen(&packet->buffer) < paddedlen)) {
2246       if (!silc_buffer_realloc(&packet->buffer,
2247                                silc_buffer_truelen(&packet->buffer) +
2248                                (paddedlen -
2249                                 silc_buffer_truelen(&packet->buffer)))) {
2250         silc_mutex_unlock(stream->lock);
2251         SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
2252         silc_mutex_lock(stream->lock);
2253         silc_packet_free(packet);
2254         memset(tmp, 0, sizeof(tmp));
2255         goto out;
2256       }
2257     }
2258
2259     /* Parse packet header */
2260     packet->flags = (SilcPacketFlags)header[2];
2261     packet->type = (SilcPacketType)header[3];
2262
2263     if (stream->sc->engine->local_is_router) {
2264       if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
2265           (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
2266         normal = FALSE;
2267       else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE ||
2268                (packet->type == SILC_PACKET_CHANNEL_MESSAGE &&
2269                 stream->is_router == TRUE))
2270         normal = TRUE;
2271     } else {
2272       if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
2273           (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
2274         normal = FALSE;
2275       else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE)
2276         normal = TRUE;
2277     }
2278
2279     SILC_LOG_HEXDUMP(("Incoming packet (%d) len %d",
2280                       stream->receive_psn, paddedlen + ivlen + mac_len),
2281                      inbuf->data, paddedlen + ivlen + mac_len);
2282
2283     /* Put the decrypted part, and rest of the encrypted data, and decrypt */
2284     silc_buffer_pull_tail(&packet->buffer, paddedlen);
2285     silc_buffer_put(&packet->buffer, header, block_len - psnlen);
2286     silc_buffer_pull(&packet->buffer, block_len - psnlen);
2287     silc_buffer_put(&packet->buffer, (inbuf->data + ivlen +
2288                                       psnlen + (block_len - psnlen)),
2289                     paddedlen - ivlen - psnlen - (block_len - psnlen));
2290     if (silc_likely(cipher)) {
2291       silc_cipher_set_iv(cipher, iv);
2292       ret = silc_packet_decrypt(cipher, hmac, stream->receive_psn,
2293                                 &packet->buffer, normal);
2294       if (silc_unlikely(ret < 0)) {
2295         silc_mutex_unlock(stream->lock);
2296         SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_DECRYPTION_FAILED);
2297         silc_mutex_lock(stream->lock);
2298         silc_packet_free(packet);
2299         memset(tmp, 0, sizeof(tmp));
2300         goto out;
2301       }
2302
2303       stream->receive_psn++;
2304     }
2305     silc_buffer_push(&packet->buffer, block_len);
2306
2307     /* Pull the packet from inbuf thus we'll get the next one in the inbuf. */
2308     silc_buffer_pull(inbuf, paddedlen + mac_len);
2309
2310     /* Parse the packet */
2311     if (silc_unlikely(!silc_packet_parse(packet))) {
2312       silc_mutex_unlock(stream->lock);
2313       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2314       silc_mutex_lock(stream->lock);
2315       silc_packet_free(packet);
2316       memset(tmp, 0, sizeof(tmp));
2317       goto out;
2318     }
2319
2320     /* Dispatch the packet to application */
2321     if (!silc_packet_dispatch(packet))
2322       break;
2323   }
2324
2325  out:
2326   /* Add inbuf back to free list, if we owned it. */
2327   if (stream->inbuf) {
2328     silc_dlist_add(stream->sc->inbufs, inbuf);
2329     stream->inbuf = NULL;
2330   }
2331
2332   silc_buffer_reset(inbuf);
2333 }
2334
2335 /****************************** Packet Waiting ******************************/
2336
2337 /* Packet wait receive callback */
2338 static SilcBool
2339 silc_packet_wait_packet_receive(SilcPacketEngine engine,
2340                                 SilcPacketStream stream,
2341                                 SilcPacket packet,
2342                                 void *callback_context,
2343                                 void *stream_context);
2344
2345 /* Packet waiting callbacks */
2346 static SilcPacketCallbacks silc_packet_wait_cbs =
2347 {
2348   silc_packet_wait_packet_receive, NULL, NULL
2349 };
2350
2351 /* Packet waiting context */
2352 typedef struct {
2353   SilcMutex wait_lock;
2354   SilcCond wait_cond;
2355   SilcList packet_queue;
2356   unsigned char id[28];
2357   unsigned int id_type     : 2;
2358   unsigned int id_len      : 5;
2359   unsigned int stopped     : 1;
2360 } *SilcPacketWait;
2361
2362 /* Packet wait receive callback */
2363
2364 static SilcBool
2365 silc_packet_wait_packet_receive(SilcPacketEngine engine,
2366                                 SilcPacketStream stream,
2367                                 SilcPacket packet,
2368                                 void *callback_context,
2369                                 void *stream_context)
2370 {
2371   SilcPacketWait pw = callback_context;
2372
2373   /* If source ID is specified check for it */
2374   if (pw->id_len) {
2375     if (pw->id_type != packet->src_id_type ||
2376         memcmp(pw->id, packet->src_id, pw->id_len))
2377       return FALSE;
2378   }
2379
2380   /* Signal the waiting thread for a new packet */
2381   silc_mutex_lock(pw->wait_lock);
2382
2383   if (silc_unlikely(pw->stopped)) {
2384     silc_mutex_unlock(pw->wait_lock);
2385     return FALSE;
2386   }
2387
2388   silc_list_add(pw->packet_queue, packet);
2389   silc_cond_broadcast(pw->wait_cond);
2390
2391   silc_mutex_unlock(pw->wait_lock);
2392
2393   return TRUE;
2394 }
2395
2396 /* Initialize packet waiting */
2397
2398 void *silc_packet_wait_init(SilcPacketStream stream,
2399                             const SilcID *source_id, ...)
2400 {
2401   SilcPacketWait pw;
2402   SilcBool ret;
2403   va_list ap;
2404
2405   pw = silc_calloc(1, sizeof(*pw));
2406   if (!pw)
2407     return NULL;
2408
2409   /* Allocate mutex and conditional variable */
2410   if (!silc_mutex_alloc(&pw->wait_lock)) {
2411     silc_free(pw);
2412     return NULL;
2413   }
2414   if (!silc_cond_alloc(&pw->wait_cond)) {
2415     silc_mutex_free(pw->wait_lock);
2416     silc_free(pw);
2417     return NULL;
2418   }
2419
2420   /* Link to the packet stream for the requested packet types */
2421   va_start(ap, source_id);
2422   ret = silc_packet_stream_link_va(stream, &silc_packet_wait_cbs, pw,
2423                                    10000000, ap);
2424   va_end(ap);
2425   if (!ret) {
2426     silc_cond_free(pw->wait_cond);
2427     silc_mutex_free(pw->wait_lock);
2428     silc_free(pw);
2429     return NULL;
2430   }
2431
2432   /* Initialize packet queue */
2433   silc_list_init(pw->packet_queue, struct SilcPacketStruct, next);
2434
2435   if (source_id) {
2436     SilcUInt32 id_len;
2437     silc_id_id2str(SILC_ID_GET_ID(*source_id), source_id->type, pw->id,
2438                    sizeof(pw->id), &id_len);
2439     pw->id_type = source_id->type;
2440     pw->id_len = id_len;
2441   }
2442
2443   return (void *)pw;
2444 }
2445
2446 /* Uninitialize packet waiting */
2447
2448 void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream)
2449 {
2450   SilcPacketWait pw = waiter;
2451   SilcPacket packet;
2452
2453   /* Signal any threads to stop waiting */
2454   silc_mutex_lock(pw->wait_lock);
2455   pw->stopped = TRUE;
2456   silc_cond_broadcast(pw->wait_cond);
2457   silc_mutex_unlock(pw->wait_lock);
2458   silc_thread_yield();
2459
2460   /* Re-acquire lock and free resources */
2461   silc_mutex_lock(pw->wait_lock);
2462   silc_packet_stream_unlink(stream, &silc_packet_wait_cbs, pw);
2463
2464   /* Free any remaining packets */
2465   silc_list_start(pw->packet_queue);
2466   while ((packet = silc_list_get(pw->packet_queue)) != SILC_LIST_END)
2467     silc_packet_free(packet);
2468
2469   silc_mutex_unlock(pw->wait_lock);
2470   silc_cond_free(pw->wait_cond);
2471   silc_mutex_free(pw->wait_lock);
2472   silc_free(pw);
2473 }
2474
2475 /* Blocks thread until a packet has been received. */
2476
2477 int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet)
2478 {
2479   SilcPacketWait pw = waiter;
2480   SilcBool ret = FALSE;
2481
2482   silc_mutex_lock(pw->wait_lock);
2483
2484   /* Wait here until packet has arrived */
2485   while (silc_list_count(pw->packet_queue) == 0) {
2486     if (silc_unlikely(pw->stopped)) {
2487       silc_mutex_unlock(pw->wait_lock);
2488       return -1;
2489     }
2490     ret = silc_cond_timedwait(pw->wait_cond, pw->wait_lock, timeout);
2491   }
2492
2493   /* Return packet */
2494   silc_list_start(pw->packet_queue);
2495   *return_packet = silc_list_get(pw->packet_queue);
2496   silc_list_del(pw->packet_queue, *return_packet);
2497
2498   silc_mutex_unlock(pw->wait_lock);
2499
2500   return ret == TRUE ? 1 : 0;
2501 }
2502
2503 /************************** Packet Stream Wrapper ***************************/
2504
2505 /* Packet stream wrapper receive callback */
2506 static SilcBool
2507 silc_packet_wrap_packet_receive(SilcPacketEngine engine,
2508                                 SilcPacketStream stream,
2509                                 SilcPacket packet,
2510                                 void *callback_context,
2511                                 void *stream_context);
2512
2513 const SilcStreamOps silc_packet_stream_ops;
2514
2515 /* Packet stream wrapper context */
2516 typedef struct {
2517   const SilcStreamOps *ops;
2518   SilcPacketStream stream;
2519   SilcMutex lock;
2520   void *waiter;                   /* Waiter context in blocking mode */
2521   SilcPacketWrapCoder coder;
2522   void *coder_context;
2523   SilcBuffer encbuf;
2524   SilcStreamNotifier callback;
2525   void *context;
2526   SilcList in_queue;
2527   SilcPacketType type;
2528   SilcPacketFlags flags;
2529   unsigned int closed        : 1;
2530   unsigned int blocking      : 1;
2531   unsigned int read_more     : 1;
2532 } *SilcPacketWrapperStream;
2533
2534 /* Packet wrapper callbacks */
2535 static SilcPacketCallbacks silc_packet_wrap_cbs =
2536 {
2537   silc_packet_wrap_packet_receive, NULL, NULL
2538 };
2539
2540 /* Packet stream wrapper receive callback, non-blocking mode */
2541
2542 static SilcBool
2543 silc_packet_wrap_packet_receive(SilcPacketEngine engine,
2544                                 SilcPacketStream stream,
2545                                 SilcPacket packet,
2546                                 void *callback_context,
2547                                 void *stream_context)
2548 {
2549   SilcPacketWrapperStream pws = callback_context;
2550
2551   if (pws->closed || !pws->callback)
2552     return FALSE;
2553
2554   silc_mutex_lock(pws->lock);
2555   silc_list_add(pws->in_queue, packet);
2556   silc_mutex_unlock(pws->lock);
2557
2558   /* Call notifier callback */
2559   pws->callback((SilcStream)pws, SILC_STREAM_CAN_READ, pws->context);
2560
2561   return TRUE;
2562 }
2563
2564 /* Task callback to notify more data is available for reading */
2565
2566 SILC_TASK_CALLBACK(silc_packet_wrap_read_more)
2567 {
2568   SilcPacketWrapperStream pws = context;
2569
2570   if (pws->closed || !pws->callback)
2571     return;
2572
2573   /* Call notifier callback */
2574   pws->callback((SilcStream)pws, SILC_STREAM_CAN_READ, pws->context);
2575 }
2576
2577 /* Read SILC packet */
2578
2579 int silc_packet_wrap_read(SilcStream stream, unsigned char *buf,
2580                           SilcUInt32 buf_len)
2581 {
2582   SilcPacketWrapperStream pws = stream;
2583   SilcPacket packet;
2584   SilcBool read_more = FALSE;
2585   int len;
2586
2587   if (pws->closed)
2588     return -2;
2589
2590   if (pws->blocking) {
2591     /* Block until packet is received */
2592     if ((silc_packet_wait(pws->waiter, 0, &packet)) < 0)
2593       return -2;
2594     if (pws->closed)
2595       return -2;
2596   } else {
2597     /* Non-blocking mode */
2598     silc_mutex_lock(pws->lock);
2599     if (!silc_list_count(pws->in_queue)) {
2600       silc_mutex_unlock(pws->lock);
2601       return -1;
2602     }
2603
2604     silc_list_start(pws->in_queue);
2605     packet = silc_list_get(pws->in_queue);
2606     silc_list_del(pws->in_queue, packet);
2607     silc_mutex_unlock(pws->lock);
2608   }
2609
2610   /* Call decoder if set */
2611   if (pws->coder && !pws->read_more)
2612     pws->coder(stream, SILC_STREAM_CAN_READ, &packet->buffer,
2613                pws->coder_context);
2614
2615   len = silc_buffer_len(&packet->buffer);
2616   if (len > buf_len) {
2617     len = buf_len;
2618     read_more = TRUE;
2619   }
2620
2621   /* Read data */
2622   memcpy(buf, packet->buffer.data, len);
2623
2624   if (read_more && !pws->blocking) {
2625     /* More data will be available (in blocking mode not supported). */
2626     silc_buffer_pull(&packet->buffer, len);
2627     silc_list_insert(pws->in_queue, NULL, packet);
2628     silc_schedule_task_add_timeout(pws->stream->sc->schedule,
2629                                    silc_packet_wrap_read_more, pws, 0, 0);
2630     pws->read_more = TRUE;
2631     return len;
2632   }
2633
2634   pws->read_more = FALSE;
2635   silc_packet_free(packet);
2636   return len;
2637 }
2638
2639 /* Write SILC packet */
2640
2641 int silc_packet_wrap_write(SilcStream stream, const unsigned char *data,
2642                            SilcUInt32 data_len)
2643 {
2644   SilcPacketWrapperStream pws = stream;
2645   SilcBool ret = FALSE;
2646
2647   /* Call encoder if set */
2648   if (pws->coder) {
2649     silc_buffer_reset(pws->encbuf);
2650     ret = pws->coder(stream, SILC_STREAM_CAN_WRITE, pws->encbuf,
2651                      pws->coder_context);
2652   }
2653
2654   /* Send the SILC packet */
2655   if (ret) {
2656     if (!silc_packet_send_va(pws->stream, pws->type, pws->flags,
2657                              SILC_STR_DATA(silc_buffer_data(pws->encbuf),
2658                                            silc_buffer_len(pws->encbuf)),
2659                              SILC_STR_DATA(data, data_len),
2660                              SILC_STR_END))
2661       return -2;
2662   } else {
2663     if (!silc_packet_send(pws->stream, pws->type, pws->flags, data, data_len))
2664       return -2;
2665   }
2666
2667   return data_len;
2668 }
2669
2670 /* Close stream */
2671
2672 SilcBool silc_packet_wrap_close(SilcStream stream)
2673 {
2674   SilcPacketWrapperStream pws = stream;
2675
2676   if (pws->closed)
2677     return TRUE;
2678
2679   if (pws->blocking) {
2680     /* Close packet waiter */
2681     silc_packet_wait_uninit(pws->waiter, pws->stream);
2682   } else {
2683     /* Unlink */
2684     if (pws->callback)
2685       silc_packet_stream_unlink(pws->stream, &silc_packet_wrap_cbs, pws);
2686   }
2687   pws->closed = TRUE;
2688
2689   return TRUE;
2690 }
2691
2692 /* Destroy wrapper stream */
2693
2694 void silc_packet_wrap_destroy(SilcStream stream)
2695
2696 {
2697   SilcPacketWrapperStream pws = stream;
2698   SilcPacket packet;
2699
2700   SILC_LOG_DEBUG(("Destroying wrapped packet stream %p", pws));
2701
2702   silc_stream_close(stream);
2703   silc_list_start(pws->in_queue);
2704   while ((packet = silc_list_get(pws->in_queue)))
2705     silc_packet_free(packet);
2706   if (pws->lock)
2707     silc_mutex_free(pws->lock);
2708   if (pws->encbuf)
2709     silc_buffer_free(pws->encbuf);
2710   silc_packet_stream_unref(pws->stream);
2711
2712   silc_free(pws);
2713 }
2714
2715 /* Link stream to receive packets */
2716
2717 SilcBool silc_packet_wrap_notifier(SilcStream stream,
2718                                    SilcSchedule schedule,
2719                                    SilcStreamNotifier callback,
2720                                    void *context)
2721 {
2722   SilcPacketWrapperStream pws = stream;
2723
2724   if (pws->closed || pws->blocking)
2725     return FALSE;
2726
2727   /* Link to receive packets */
2728   if (callback)
2729     silc_packet_stream_link(pws->stream, &silc_packet_wrap_cbs, pws,
2730                             100000, pws->type, -1);
2731   else
2732     silc_packet_stream_unlink(pws->stream, &silc_packet_wrap_cbs, pws);
2733
2734   pws->callback = callback;
2735   pws->context = context;
2736
2737   return TRUE;
2738 }
2739
2740 /* Return schedule */
2741
2742 SilcSchedule silc_packet_wrap_get_schedule(SilcStream stream)
2743 {
2744   return NULL;
2745 }
2746
2747 /* Wraps packet stream into SilcStream. */
2748
2749 SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
2750                                    SilcPacketType type,
2751                                    SilcPacketFlags flags,
2752                                    SilcBool blocking_mode,
2753                                    SilcPacketWrapCoder coder,
2754                                    void *context)
2755 {
2756   SilcPacketWrapperStream pws;
2757
2758   pws = silc_calloc(1, sizeof(*pws));
2759   if (!pws)
2760     return NULL;
2761
2762   SILC_LOG_DEBUG(("Wrapping packet stream %p to stream %p", stream, pws));
2763
2764   pws->ops = &silc_packet_stream_ops;
2765   pws->stream = stream;
2766   pws->type = type;
2767   pws->flags = flags;
2768   pws->blocking = blocking_mode;
2769   pws->coder = coder;
2770   pws->coder_context = context;
2771
2772   /* Allocate small amount for encoder buffer. */
2773   if (pws->coder)
2774     pws->encbuf = silc_buffer_alloc(8);
2775
2776   if (pws->blocking) {
2777     /* Blocking mode.  Use packet waiter to do the thing. */
2778     pws->waiter = silc_packet_wait_init(pws->stream, NULL, pws->type, -1);
2779     if (!pws->waiter) {
2780       silc_free(pws);
2781       return NULL;
2782     }
2783   } else {
2784     /* Non-blocking mode */
2785     silc_mutex_alloc(&pws->lock);
2786     silc_list_init(pws->in_queue, struct SilcPacketStruct, next);
2787   }
2788
2789   silc_packet_stream_ref(stream);
2790
2791   return (SilcStream)pws;
2792 }
2793
2794 const SilcStreamOps silc_packet_stream_ops =
2795 {
2796   silc_packet_wrap_read,
2797   silc_packet_wrap_write,
2798   silc_packet_wrap_close,
2799   silc_packet_wrap_destroy,
2800   silc_packet_wrap_notifier,
2801   silc_packet_wrap_get_schedule,
2802 };